Area-specific fertilizer recommendations for hybrid maize grown by Malawian smallholders
A Manual for Field Assistants
by Action Group I
Maize Productivity Task Force
Maize Commodity Team - Chitedze Agricultural Research Station
and member of Action Group I, Maize Productivity Task Force
In 1997 preliminary area-specific fertilizer recommendations were given to all Extension
Field Assistants as part of their training for the nationwide 1997/98 Maize Fertilizer
Recommendations Demonstration. This Demonstration was successfully implemented, and the
results were used to assess the value of the preliminary fertilizer recommendations. As a result
of this assessment, changes have been made to the recommendations so that they will be easier
for farmers to use. These new recommendations presented here are the ones which you will be
using with farmers for the foreseeable future and represent the end of the work of Action Group I
of the Maize Productivity Task Force on developing area-specific recommendations.
This manual presents the new recommendations along with necessary information on
how to make use of them with farmers growing hybrid maize. There are two principal changes to
the area-specific recommendations relative to those which you were given in 1997:
1) General soil texture no longer appears as a consideration in the base recommendations.
However, separate recommendations are still provided for the two different production
aims of the farmer. Consequently, rather than four possible fertilizer recommendations
for an Extension Planning Area (EPA), now there are only two.
2) Rates of application have been revised for some EPAs.
It might have been expected that all these recommendations would consist of is a map or
table showing the fertilizer recommendation that applies in each EPA of the country.
Unfortunately the rapid economic changes which are currently taking place in Malawi mean that
the recommendations must be more than that. The economic conditions of today will not be the
same as we experience next year. Consequently, the optimal rates – the most profitable rates of
fertilizer for farmers to use – this year will not necessarily be the right ones for farmers to use
next year. This document does present two basic area-specific fertilizer recommendations for
The members of Action Group I during the period these recommendations were developed were
J.D.T. Kumwenda (chairman), K.M. Chavula, A.D.C. Chilimba, A.C. Conroy, R.A. Gilbert, A. Gomez, R.B. Jones,
V.H. Kabambe, the late E.E. Kanyenda, S.K. Mughogho, B.J. Sizilande, and T.D. Benson.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 2
each EPA, but it then goes on to provide you with knowledge and tools to use in modifying these
recommendations to make them more appropriate for the particular circumstances farmers might
face in your area. Thus this manual is much more than simply recommended rates of fertilizer
application for maize.
The manual is divided into the following sections:
WHY AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR HYBRID MAIZE? ...................................2
FERTILIZER RECOMMENDATIONS DECISION TREE .............................................................................3
ECONOMICS AND APPROPRIATE FERTILIZER APPLICATION ...............................................................5
THE PRICES USED FOR MAIZE AND FERTILIZER IN DEVELOPING THE RECOMMENDATIONS ...............8
THE BASIC AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR HYBRID MAIZE ..........................11
USING CREDIT OR USING ONES OWN CASH FOR ACQUIRING FERTILIZER .........................................14
HOW FARMERS CAN MAKE THE BEST USE OF THEIR FERTILIZER ON MAIZE ....................................15
HOW TO APPLY THE PROPER AMOUNT OF FERTILIZER TO MAIZE ....................................................21
HYBRID SEED OR LOCAL SEED? ......................................................................................................22
CLOSING REMARKS ........................................................................................................................24
APPENDIX – PATTERN OF AREA-SPECIFIC FERTILIZER RECOMMENDATIONS WITHIN ADDS...........25
Why area-specific fertilizer recommendations for hybrid maize?
In the 1980s many farmers in Malawi began to grow hybrid maize using fertilizer. Field
Assistants advised farmers throughout the country that they should apply 87 kg of Di-ammonium
Phosphate (DAP) fertilizer and 175 kg of urea fertilizer per hectare of hybrid maize. This rate
provides the crop with 96 kg of nitrogen and 40 kg of phosphate per hectare.
Several problems with this blanket recommendation were recognized by farmers,
extension officers, and agricultural scientists:
• Malawi is a diverse country in climate and in soils. The blanket recommendation does not
The amount of extra maize which farmers receive from applying fertilizer differs from
place to place depending on the rainfall received and the soil upon which the maize is
grown. For example, one should not expect that a fertilizer rate appropriate for farmers
growing maize near Kasungu would also be suitable for those growing maize near Balaka.
The environments in the two areas are very different – neither the rainfall patterns nor the
soils are the same. Different fertilizer recommendations should apply to each area.
• The rates given in the blanket recommendation are not profitable for many farmers to use.
In many areas of the country the cash from the sale of the additional maize which
farmers received from using fertilizer at the old recommended rate was not enough to repay
the credit used in buying the fertilizer. Once the fertilizer credit was repaid, little additional
maize was left for the farmer’s own use. Many farmers found that lower rates of fertilizer
application were more profitable. In recent years as prices of fertilizer have doubled or
tripled, the recommended blanket rate has become even less profitable.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 3
• Agronomically, the nutrients in the blanket recommendation are not well balanced.
• Nitrogen is the most important nutrient required by maize. The emphasis in the
blanket recommendation on nitrogen is appropriate. The problem is that for many
areas of the country the rate recommended is too high.
• However, maize in most areas of Malawi does not benefit from rates of phosphate
above 20 kg/ha. Lower rates than the 40 kg/ha recommended are more appropriate.
• Moreover, sulphur is not provided in the blanket recommendation of DAP and urea.
Maize in Malawi requires some sulphur for optimal growth.
Out of the work of Extension Field Assistants in implementing the nationwide 1995/96
Fertilizer Verification Trial and the 1997/98 Maize Fertilizer Recommendations Demonstration,
area-specific recommendations have now been developed and approved by the Ministry of
Agriculture and Irrigation. The basic area-specific recommendations are presented in maps and
tables later in this manual.
However it is very important to realize that the recommendations as shown in the maps
are only the starting point. For many farmers the basic area-specific recommendations will be no
better for their particular circumstances than was the blanket fertilizer recommendation. Of
equal importance to the farmer using the recommendations is how to modify them to suit their
particular needs and to provide maximum benefit to his or her household. The manual provides
guidelines as to how the recommendations should be modified to make them worthwhile for a
particular farmer, farming in a specific area, with particular resource constraints, and facing
different and often changing prices for fertilizer and maize.
Fertilizer recommendations decision tree
The decision tree diagram in Figure 1 shows how the appropriate fertilizer
recommendation for a farmer is determined. In contrast to the blanket recommendation which
these area-specific recommendations replace, a maize field in Malawi does not have only one
rate of fertilizer applicable. Rather, two recommended rates are offered. The one a farmer
chooses depends on why the farmer is producing maize.
In order to use the basic area-specific fertilizer recommendations, a farmer needs to
know two things:
1) The EPA in which the farmer is growing the maize. The area-specific recommendations
apply to Extension Planning Areas or to larger agricultural extension districts – Rural
Development Projects (RDP) or Agricultural Development Divisions (ADD).
Consequently, the farmer needs to know in which EPA he or she is farming. Location is
important when considering fertilizer use: Where one is in Malawi determines what sort
of weather and general soil conditions the farmer should expect.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 4
• Figure 1: Decision tree underlying the recommendations
For Home For Market
2) The production aim of the farmer. The production aim of the farmer is either for home
consumption and use or for sale at the market. The farmer places a different value on the
maize depending on what is the intended use of the maize. If producing for the market, a
reasonable value for the maize is the producer price which the farmer will receive in the
market. However, if the farmer is producing for home use, the significantly higher
consumer maize price is the value of the maize, as every kg of maize the farmer produces
in his or her own field is one less that will have to be purchased in the market at the
consumer maize price and transported back home. As this price is considerably higher
than the producer price, it makes economic sense for the farmer to apply higher rates of
fertilizer to the maize when producing for home consumption. As will be seen, the
recommendations reflect this. The economic reasons for why two different
recommendations result from the two prices will be given in the next section.
However, many farmers will be producing both for market sale and for home
consumption. The recommendations presented here are maximum fertilizer application
rates when producing purely for either of the two aims. For mixed production where
some maize from the field goes for home consumption and some for market sale, a
reasonable fertilizer level between the two recommendations for a particular field should
With these two pieces of information, one can determine the appropriate basic fertilizer
recommendation for the farmer to use on his or her hybrid maize. Basic is underlined because
figuring out the best recommendation for a farmer does not end with the maps. The basic
recommendation from the maps should be evaluated in light of two important factors:
1) The fertilizer to maize price-ratio in the area. Is it higher, lower, or the same as that
which was used to develop the basic area-specific fertilizer recommendations? As will
be discussed, the basic recommendation should be adjusted if it is not the same.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 5
2) The amount of cash the farmer has. Can she or he afford the entire recommended
fertilizer package with cash on hand or credit ? If not, how should the available cash of
the farmer be used on fertilizer?
Economics and appropriate fertilizer application
Determining which rates of fertilizer should be recommended for maize in a particular
area is not accomplished using some sort of magic or difficult scientific processes. Rather, the
common sense approach is followed of making sure that the net benefits which the farming
household will enjoy from the use of fertilizer will be the highest possible. The net benefit is the
value of the maize produced after you have subtracted the cost of the fertilizer:
Net benefit = ([bags of maize harvested] x [price of maize per bag]) - cost of fertilizer
The level of the net benefits which a household achieves are determined by:
• the conditions under which the fertilized maize was grown,
• the cost of fertilizer,
• the value of maize for the household.
As such, fertilizer recommendations are derived by a combination of agronomy and economics.
The agronomic aspect lies in the response in maize yield to fertilizer. That is, if I put
one kg of fertilizer on my maize, how many additional kg of maize would I receive?
The level of the response is determined by a wide range of factors. The most important,
however, are the condition of the soil, particularly its natural fertility; the weather conditions of
the particular growing season; and the management of the maize by the farmer – adequate
weeding, early planting, timely fertilizer application, and so on.
An important aspect of the response of maize to fertilizer is that the level of response
declines as more fertilizer is applied to the maize. This is an example of the law of diminishing
returns. The law of diminishing returns can be portrayed in two ways using the average maize
yields from the 1995/96 Fertilizer Verification Trial from across the country.
First, Figure 2 is the graph of average maize yields per hectare across the country for the
treatments of the Trial where: i) no fertilizer was applied; ii) 100 kg/ha of fertilizer was applied,
iii) 200 kg of fertilizer was applied; and iv) 250 kg of fertilizer was applied. If the law of
diminishing returns did not apply, the line should be straight. However, it is not straight, but it
curves downwards. This means that for every additional amount of fertilizer you apply, you get
less maize yield for that fertilizer than what you received at lower rates of application. The
greatest response in maize yield to fertilizer occurs at the lowest rates of fertilizer application.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 6
• Figure 2: Average yields of Fertilizer Verification Trial
and the law of diminishing returns
Maize yield (kg/ha)
0 100 200 300
Secondly, the right column in Table 1 shows the average maize yield which was received
in the Verification Trial per kg of fertilizer applied at different rates. The way these numbers are
calculated is by taking the maize yield for a particular fertilizer application level and subtracting
the maize yield when no fertilizer is applied (0 kg/ha). The result is then divided by the rate of
fertilizer applied. For example, at 200 kg/ha, the kg increase in maize yield per kg of fertilizer
applied is (2880 - 1410) ÷ 200 = 1470 ÷ 200 = 7.4. Again, if the law of diminishing returns
did not apply, the numbers in the column to the right would all be the same. However, they
become smaller as the rate increases. If one extends the trend, agronomically this means that at
some higher level of application, no additional maize yield will result from adding fertilizer.
As a consequence of this agronomic feature of fertilizer use, economically there will also
be a rate of fertilizer application, much lower than the agronomic maximum level, where no
additional net benefit will result from applying more fertilizer. This rate is where the value to
the farmer of any additional maize produced will be less than the cost of any additional fertilizer
applied to the maize. It is this level of fertilizer application which should be the maximum rate
recommended for farmers.
The recommended rate of fertilizer application, consequently, is determined to a large
• Table 1: The law of diminishing returns in fertilizer application to
average kg increase in
average maize yield maize yield per kg
fertilizer application level (kg/ha) fertilizer applied
0 kg/ha 1410 --
100 kg/ha (50 kg 23:21:0+4S & 50 kg urea) 2360 9.5
200 kg/ha (100 kg 23:21:0+4S & 100 kg urea) 2880 7.4
250 kg/ha (100 kg 23:21:0+4S & 150 kg urea) 3150 6.9
It is important to realize that these yields are average yields and reflect very good management of the maize.
Particularly for the upland areas of Malawi where most of the maize is grown in the country, the yields which
farmers should expect when no fertilizer is applied will be considerably lower than that shown here
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 7
degree by the cost of the fertilizer used and the value of the maize for the farmer – usually the
price of maize at the market. For example, if the price of fertilizer is very high while the price of
maize is very low, then only very low levels of fertilizer use can be profitable. In a situation of
extremely high fertilizer prices and low maize prices, as might happen following a year with a
very good maize harvest, it might well be wiser for the farmer not to use fertilizer, but to take the
money which could be spent on fertilizer for maize and purchase grain instead.
Fundamentally, it is the ratio of the price of fertilizer to the price of maize which
determines the optimum level of fertilizer application for a farmer. This ratio is the price of
fertilizer per bag (for example, urea) divided by the price of maize per bag, both bags being the
same weight. If prices change, and the ratio of the price of fertilizer to the price of maize no
longer is what it was when the fertilizer recommendations originally were made, then the optimal
level of fertilizer application will also have changed and the fertilizer recommendations should
The relationship between the direction in which the price-ratio changes and the direction
in which the optimal fertilizer application rate should change is an inverse relationship. This
If the fertilizer to maize price-ratio goes up, the recommended level of fertilizer
application will be lower than previously.
If the fertilizer to maize price-ratio goes down, the recommended rate of
application will be higher.
You might ask, “What does all of this economics have to do with the new area-specific
fertilizer recommendations?” It has been presented principally for three reasons:
1) The basic area-specific fertilizer recommendations presented later in this document
were derived in a manner similar to that sketched out here. In essence, net benefits were
calculated from the maize yields resulting from the four rates of fertilizer applied in both
the 1995/96 Fertilizer Verification Trial and the 1997/98 Maize Fertilizer
Recommendations Demonstration. That fertilizer rate which gave the greatest net
benefit for fields in a particular zone was judged to be the appropriate recommendation.
2) The decision tree upon which the area-specific recommendations are based uses two
different values for maize – the producer price and the consumer price – which
correspond to the two production aims a farmer might choose. Consequently, two
different fertilizer to maize price-ratios are used and, subsequently, two different optimal
rates of fertilizer application result – one which is applicable when the farmer values the
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 8
maize for its use in home consumption, and a second when it is valued at the price it will
fetch when sold at the market.
3) Prices for maize and fertilizer in Malawi will continue to change in the future, just as
they have in the past, so optimal rates of fertilizer application on maize will change
frequently as well. This is the most important reason why all extension officers and
farmers should understand how the economics of fertilizer use determine the rate one
In order to provide good fertilizer recommendations to farmers, extension
officers must have an understanding of how changing price-ratios for fertilizer and maize
change the optimal level of fertilizer application on maize in a recommendation zone. In
order to use these recommendations effectively, one must be aware of the fertilizer to
maize price-ratios upon which the area-specific fertilizer recommendations were
developed. These are given in the next section. Knowing these, extension officers and
farmers should then calculate the price-ratios for their area, compare them to those used
to develop the recommendations, and change the recommendations as is appropriate.
The prices used for maize and fertilizer in developing the recommendations
Price changes will mean different optimal recommendation levels depending upon how
the maize and fertilizer prices change relative to each other. Paying attention to the changes in
the ratio of the price of fertilizer to the price of maize is the key thing. (Remember, the price-
ratio is the price of fertilizer divided by the price of maize.) For example:
• If both maize prices and fertilizer prices rise or fall by equal proportions or
percentages, the price-ratio will stay the same. The recommendations which were
appropriate before still will remain appropriate.
• A lower price-ratio than that upon which the recommendations are based means that
higher rates of fertilizer can be used. Lower price-ratios can result from:
• Maize prices rise without the fertilizer price changing.
• Maize prices stay the same, but fertilizer prices fall.
• Fertilizer prices rise, but maize prices also rise and by a greater proportion.
• Maize prices rise, and fertilizer prices fall. And so on.
• A higher price-ratio means that lower rates of fertilizer than were previously applied
should be used. Higher price-ratios also can come about in many ways:
• Fertilizer prices rise, while maize prices do not rise by the same proportion.
• Maize prices drop, while fertilizer prices stay the same.
• Fertilizer prices rise, while the price of maize does not. And so on.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 9
If the actual fertilizer to maize price-ratio in your area is significantly different from the
price-ratios used to calculate the basic recommendations, you should adjust the basic
recommendation for your area to make it more appropriate.
Prices used for the recommendations for home consumption production aim
The home consumption recommendations were calculated based upon the prices for urea
and 23:21:0+4S fertilizers and the consumer price of maize. The consumer price is that price
which you pay when you go to the market to buy a bag of maize for your own use – not the price
which merchants will give you when they buy maize you harvested.
The prices used in calculating the recommendations which apply when the production
aim is for home consumption were as follows:
consumer price of maize: MK 362.50 per 50 kg bag
urea: MK 840.00 per 50 kg bag
23:21:0+4S: MK 895.00 per 50 kg bag
The easiest way to keep track of the fertilizer to maize price-ratio is to use urea as a
general indicator of fertilizer prices. In general the price of 23:21:0+4S and other fertilizer
should change in a similar manner to the price of urea. The price of 23:21:0+4S is shown here
simply for later reference.
The urea to maize price-ratio used to develop the for home consumption fertilizer
recommendations was MK 840 ÷ MK 362.50 = 2.3.
If you find that the price-ratio in your area is significantly different than this ratio, the
rate of fertilizer which you use or which you advise farmers to use should be changed from the
basic rates recommended. As a rough guide to determine whether the difference in price-ratio is
significant or not, if the difference is over 15 percent, consider adjusting the fertilizer application
rates. That is, you should use somewhat less fertilizer than the basic recommendation if the urea-
to-maize price-ratio is above 2.6. More can be used if the price-ratio is less than 2.0.
How much less fertilizer should be applied under higher price-ratios depends on how
high the price-ratio in your area is relative to that used to develop the recommendation. If the
difference is 15 percent higher, consider the next smaller package of fertilizer. For example, if
the basic recommendation is 69:21:0+4S, use 35:10:0+2S instead.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 10
Prices used for the recommendations for market sale production aim
The market sale recommendations were calculated based upon the fertilizer prices and
the producer price of maize. The producer price is that price which merchants will give you
when they buy the maize you harvested and have brought to market.
In determining what rate of fertilizer should apply when one will be selling the maize at
the market, the fertilizer prices remained the same as above. However, the maize price used was
MK 262.50 per 50 kg bag.
The urea to maize price-ratio used to develop the for market sale fertilizer
recommendations was MK 840.00 ÷ MK 262.50 = 3.2.
Again, use 15 percent in determining whether the difference in price-ratio is significant
or not. That is, you can use somewhat more fertilizer than the basic recommendation when
producing for the market if the price-ratio is less than 2.7. Less should be used if the price-ratio
is more than 3.7. In fact, once the price-ratio rises above 4.0, rarely can fertilizer use be
recommended for most farmers growing maize for sale.
Estimated future maize prices should be used
Realize that the maize price which should be used in making the calculation of the price-
ratio is not the current price of maize, but the price after the harvest which you and the farmer
expect. It is that price which determines whether or not the use of fertilizer on the growing
maize was a wise and profitable thing to do. As no one knows before the rains come what maize
prices will be like after the harvest, the best you can do is estimate this maize price.
However, in estimating maize prices, remember that maize prices change as time passes
from the harvest. Prices are lowest immediately after harvest, but can be very high just before
the next harvest. Which price should be used? Use an estimate of what you expect the maize
price will be at the time after harvest when the farmer typically sells or buys maize in the market.
For example, if he will be producing for the market and will need to repay a loan immediately
after harvest, then use as an estimate the low producer price common at that time.
Finally, different merchants offer different prices in the market. ADMARC gives one;
large, full-time traders give another; and small, part-time traders give others. Whose prices
should you base your estimates upon? Use those of the merchant with whom the farmer would
typically deal. For many farmers, if they buy or sell in small quantities, they will not receive the
relatively good prices which ADMARC or large traders will offer, but must be content with the
lower producer prices or higher consumer prices of the small, part-time traders.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 11
The basic area-specific fertilizer recommendations for hybrid maize
The recommendations are presented in list form by Agricultural Development Division
(ADD) and Rural Development Project (RDP) in Table 2 and in maps in Figure 3.
The recommendations are based upon four rates of fertilizer: nil; 35:10:0+2S;
69:21:0+4S; and 92:21:0+4S. These numbers correspond respectively to the kilograms of
nitrogen : phosphate : potassium + sulphur (S) applied per hectare in the fertilizer.
The rates are based upon the use of the fertilizers 23:21:0+4S and urea (46% nitrogen).
As shown in Table 3, the rate 35:10:0+2S corresponds to the application of one bag of
• Table 2: Area-specific fertilizer recommendations, by ADD, RDP, and
Market Sale Home Consumption
ADD RDP EPA Recommendation Recommendation
Karonga Chitipa All, except Misuku 35:10:0+2S 69:21:0+4S
Misuku Nil 69:21:0+4S
Karonga All Nil 35:10:0+2S
Mzuzu Rumphi – North Mpherembe, Bwengu, 35:10:0+2S 92:21:0+4S
Mzimba Zombwe, Bolero
Muhuju, Nchenachena/Phoka Nil 69:21:0+4S
Central Mzimba All 35:10:0+2S 92:21:0+4S
South Mzimba All 35:10:0+2S 92:21:0+4S
Nkhata Bay All, except Mpamba Nil 35:10:0+2S
Mpamba Nil 69:21:0+4S
Kasungu All All 35:10:0+2S 92:21:0+4S
Lilongwe All All 35:10:0+2S 92:21:0+4S
Salima Salima All 35:10:0+2S 92:21:0+4S
Nkhotakota Nkhunga, Linga Nil 69:21:0+4S
Zidyana, Mwansambo 35:10:0+2S 92:21:0+4S
Bwanje All 35:10:0+2S 92:21:0+4S
Machinga Mangochi All 35:10:0+2S 69:21:0+4S
Namwera All 35:10:0+2S 69:21:0+4S
Balaka Ulongwe, Mpilisi 35:10:0+2S 69:21:0+4S
Bazale, Phalula, Rivi-rivi 35:10:0+2S 92:21:0+4S
Kawinga All 35:10:0+2S 69:21:0+4S
Zomba All, except Mtubwi, Chingale 35:10:0+2S 92:21:0+4S
Mtubwi, Chingale 35:10:0+2S 69:21:0+4S
Blantyre Shire Highlands All, except Lirangwe 35:10:0+2S 92:21:0+4S
Lirangwe 35:10:0+2S 69:21:0+4S
Thyolo All 35:10:0+2S 92:21:0+4S
Mulanje All 35:10:0+2S 92:21:0+4S
Phalombe All 35:10:0+2S 92:21:0+4S
Mwanza All 35:10:0+2S 69:21:0+4S
Shire Valley All All Nil 35:10:0+2S
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 12
• Figure 3: Area-specific fertilizer recommendations for hybrid maize
grown by smallholders
Market Sale Home Consumption
Recommended per ha production aim production aim
1 bag of 23:21:0+4S
1 bag of urea per hectare.
2 bags of 23:21:0+4S
2 bags of urea per hectare.
2 bags of 23:21:0+4S
3 bags of urea per hectare.
(50 kg bags of fertilizer)
Unshaded areas are non-
agricultural – lakes, cities, forest
reserves, or national parks.
Boundaries of the ADDs are
23:21:0+4S and one bag of urea per hectare, while 69:21:0+4S results from applying two bags of
each, and 92:21:0+4S is the amount of nutrients applied from two bags of 23:21:0+4S and three
bags of urea per hectare. The most common recommendation if producing for home
consumption is 92:21:0+4S, while 35:10:0+2S is the general recommendation when growing
maize for the market.
When the two maps of Figure 3 are combined into one map, four separate sets of the two
production aim recommendations are required to cover all areas of the country, as is shown in
Figure 4. The image is rather complex when examined at the national scale. However, when you
look at it at the level of the Agricultural Development Division (ADD) or the even smaller RDP,
the pattern is considerably simplified. Of the thirty-one RDPs in Malawi, only seven of them
have been assigned more than one set of recommendations. Moreover, the complexity in the
recommendation pattern for these few RDPs usually is because they cover two or more
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 13
• Figure 4: Area-specific fertilizer recommendation zones of Malawi
Market Sale Consumption
Fertilizer recommendations for hybrid
maize in kg of N:P2O5:K+S per hectare.
Unshaded areas are non-agricultural.
ADD boundaries shown.
ecological zones which have different fertilizer response patterns. As most extension officers
operate within the section or the EPA, you should find the recommendation scheme to be
Note that these rates are maximums, rather than all-or-nothing recommendations. Lower
rates of fertilizer than those recommended will provide the farmer with good returns in maize
yield or income. Application rates up to the levels indicated in all but the worst years will
provide the farmer with an attractive return. Field Assistants should advise farmers, particularly
when producing for home consumption, that a little fertilizer is a worthwhile addition to the
maize crop, even if not applied at the maximum level recommended.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 14
• Table 3: Fertilizers of However, higher rates of application
place the farmer at considerable risk of losing
Bags of fertilizer
money on the use of fertilizer, particularly when
Recommendation per hectare
weather conditions are poor. In this light, the
23:21 Urea most interesting parts of the maps in Figure 3
35:10:0+2S :0+4S &
50 kg 50 kg
are particularly where lower rates of fertilizer
It is important to note that these
50 kg 50 kg
recommendations are generalizations. They
69:21:0+4S & assume a single ecological zone in each EPA.
Several EPAs in Malawi have two or more
50 kg 50 kg
ecological zones in which maize is grown. The
Appendix highlights where in particular EPAs
23:21 23:21 modifications to these recommendations should
50 kg 50 kg
be made based on variability in growing
92:21:0+4S conditions within EPAs.
Urea Urea Urea Using credit or using ones own cash for
50 kg 50 kg 50 kg acquiring fertilizer
The price that one pays for fertilizer is
not the only cost which a farmer faces when using fertilizer. The most important of these other
costs is that of credit – how the farmer acquires sufficient cash to pay for the fertilizer in the first
place. The two different production aims have significantly different credit costs.
First, if the farmer is producing for the market, it is assumed that the farmer expects that
the maize produced will pay fully for all costs, including the cost of acquiring the cash to
purchase the fertilizer – that is, the cost of credit. Consequently, it is very important to bear in
mind when using these recommendations that if the farmer is producing maize using fertilizer
acquired through commercial credit (MRFC or the like), then the ‘market production’
recommendations must be used. Those recommendations incorporate the full costs of this credit
in determining the level of fertilizer to apply. The ‘home consumption’ recommendations do not.
Unfortunately, it is very likely that the farmer using credit will not be able to pay back the loan if
he or she uses higher rates of fertilizer than those given under the ‘market production’ production
If annual credit interest rates for farmers rise significantly, this will increase the total
cost of the fertilizer, and increase the fertilizer to maize price-ratio. If credit rates rise above 50
percent, then farmers should apply lower rates than recommended in the market production basic
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 15
recommendations. However, as noted above, at higher price-ratios, it is unlikely to be profitable
for farmers to apply fertilizer to maize which is to be sold at the market.
Secondly, if the farmer is producing maize with fertilizer for home consumption, it is
assumed that the cash for purchasing the fertilizer did not come from commercial credit. Rather,
the farmer acquired the money from another cash-producing activity of the household. This most
commonly would be from tobacco or cotton production, but could also be from wage labour and
ganyu, cash gifts from family members working in urban areas, or some other source. The cash
used for the fertilizer is not being treated as an investment from which a profitable return will be
produced. Rather, it is being consumed for household welfare, after first using it for fertilizer to
acquire in the end considerably more maize than could be directly purchased with the money.
However, extension officers particularly should be clear about the difficulties of
purchasing fertilizer with ones own cash. Field Assistants and other extension officers are paid a
salary from which they can purchase fertilizer. Their civil service position is the “cash-
producing activity” noted above from which the fertilizer is purchased when it is to be used to
produce maize for home consumption. However, for most rural households, where does this
money come from? Unless they grow a cash crop, most farmers are unable to accumulate the
money required to purchase the amount of fertilizer recommended for the home consumption
production aim. Many households will have few cash-producing options beyond ganyu, which in
itself may be insufficient to allow the household to meet all of its other cash needs and buy
fertilizer as well.
That said, remember that the recommendations noted in the basic recommendation maps
should be seen as maximums. Even if farmers are unable to put the recommended amount on
their maize, smaller amounts of fertilizer will provide them with a good return. Farmers should
be encouraged to put on the amount of fertilizer which they can afford.
In summary, changes in credit costs should be considered when developing an
appropriate fertilizer recommendation for maize being grown for market sale, particularly if the
interest rates charged by rural credit lenders rise above 50 percent. However, for production of
fertilized maize for own household use, the cost of credit is irrelevant so long as one recognizes
that the cash to buy the fertilizer must come from some other cash-producing activity of the
household, and not credit.
How farmers can make the best use of their fertilizer on maize
Fertilizer is much more expensive now than it was in the 1980s and early 1990s.
Farmers who regularly were able to afford to apply recommended rates of fertilizer in the past
are no longer able to do so. Yet, farmers recognize that fertilizer helps them achieve the maize
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 16
yields they require to feed their families. They need to be confident in how they can make the
best use of whatever amount of fertilizer they can afford. What follows are a few guidelines.
Good farming practices
Regardless of how much or how little fertilizer farmers are able to use on their maize,
they must do a good job in growing the maize. This means early planting, on-time application of
fertilizer, and, most importantly, good weeding. These points are emphasized to farmers over
and over again, but they remain a critical aspect of fertilizer use.
• Plant early.
• To maximize the returns in maize yield to expensive fertilizer, make sure that
the crop to be fertilized is planted on time with the first good rains. Any
delays in planting mean lower harvests.
• Fertilizer must be applied properly and on time.
• The basal application of 23:21:0+4S fertilizer is best applied before planting.
However, as most farmers are not willing to apply fertilizer until they first see
the maize plants emerge, inform them that it must be put on immediately after
emergence. When the maize is young is when it needs the phosphate that is
applied in the basal fertilizer.
• The top-dressing of urea should be applied three to four weeks after the basal
dressing. Do not delay more than that. The later the top-dressing is applied,
the more the nitrogen in the fertilizer goes into the leaves and stalk of the
plant, rather than into the grain.
• Particularly with urea, be careful that the fertilizer is not placed in
contact with the maize seedling. Urea can burn the seedling, possibly
even killing it. It should be placed about 10 cm away from the plant.
• Urea should also be covered with soil after application. Otherwise,
some of the nitrogen in the urea will be lost to the air.
• Two good weedings should be done on the maize. The first should be done as soon
as the first weeds appear, within three weeks after planting. The second weeding
should be done three to four weeks later. It makes sense to weed well when using
fertilizer: Why fertilize weeds?
• Rather than putting on a lot of fertilizer and weeding poorly, a farmer would
be wiser to put on less fertilizer and use the money saved on fertilizer to hire
ganyu labourers to weed the crop well. A larger maize harvest will result.
Pay attention to the general soil texture of the maize field
Soil conditions affect the level of response to fertilizer. Soil texture serves as an
important indicator of several soil characteristics which affect the level of maize yield response
to fertilizer, and so affect the profitability of using fertilizer. Light-textured or sandy soils
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 17
typically are less fertile than medium-textured soils (loams and clays), so respond well to
fertilizer when growing conditions are good. Medium-textured soils are not quite as responsive
to fertilizer as light-textured soils, but they typically are less risky soils upon which to use
fertilizer – they are less affected by drought and fertilizer does not leach so readily from them
under heavy rains. Consequently, medium-textured soils are the preferred soils for fertilizer use
in most parts of Malawi.
Which fertilizer to buy
The area-specific fertilizer recommendations for hybrid maize are based upon the use of
urea and 23:21:0+4S. A farmer with only a small amount of money will not be able to afford
both. Which one should the farmer buy?
In Malawi, if maize requires fertilizer, in the great majority of cases it requires nitrogen
first of all. Researchers from Chitedze have shown this over and over. Phosphate and sulphur
are important, but the main response in maize yield to the application of fertilizer comes from the
nitrogen in the fertilizer, rather than from the other two nutrients. Consequently, a farmer who
cannot purchase the entire recommended fertilizer package should use his or her limited cash to
buy the fertilizer which provides the most nitrogen for the least cost. In Malawi at present, this
fertilizer is urea.
When applying only urea, the farmer should apply the fertilizer soon after emergence. If
more than a bag of urea is applied, in order to avoid much of the fertilizer being leached –
washed out of the rooting zone of the soil – or washed away by heavy rains, it is best to apply the
fertilizer in split doses. That is, half of the fertilizer should be applied soon after emergence,
with the remaining fertilizer being applied three to four weeks later.
Applying nitrogen alone is not the best way of managing soil fertility for maize, and
should be seen only as a short term strategy for farmers. If the farmer applies only nitrogen alone
every year for several years, eventually sulphur and phosphorus deficiencies will begin to reduce
maize yields. As a rough guideline, farmers should apply 23:21:0+4S or another fertilizer
containing phosphate and sulphur every two or three years if using only nitrogen in other years.
Kasungu, Mzimba, and Chitipa are known as areas in which phosphorus deficiencies are more
common than elsewhere, so in those areas farmers should apply phosphate and sulphur every
Fertilizer prices change. The other main nitrogen-containing fertilizers which
smallholders might use in Malawi are Calcium Ammonium Nitrate (CAN) and Ammonium
Sulphate (AS, also called Sulphate of Ammonia). In the future possibly one of these fertilizers
or some other fertilizer may become a cheaper source of nitrogen than the urea used in these
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 18
recommendations. In order to be able to determine whether this might be the case, farmers
should know how to compare fertilizers in terms of the cost of the nitrogen they supply:
• Per bag, the two other fertilizers are cheaper than urea: CAN sold for about MK 695
per bag and AS for about MK 620 per bag in 1998/99, versus MK 840 for urea.
• However, urea contains more nitrogen. Urea has 46% nitrogen, the best CAN
contains 28% nitrogen, and AS has 21% nitrogen. The nitrogen content of the
fertilizer is usually printed on the fertilizer bag. A 50 kg bag of urea will contain 23
kg of nitrogen, a bag of CAN will contain 14 kg of nitrogen, and a bag of AS will
contain 11.5 kg of nitrogen.
• To calculate the price of one kg of nitrogen from the different sources, you divide the
price of a bag of fertilizer by the number of kg of nitrogen it contains. The cost of
one kg of nitrogen in 1998/99 as urea was MK 840 ÷ 23 = MK 36.52, as CAN the
nitrogen cost MK 695 ÷ 14 = MK 49.64, and as AS it was MK 620 ÷ 11.5 =
MK 53.91. At current prices, urea is the cheapest fertilizer nitrogen for your maize.
However, many farmers prefer using CAN or AS to urea. Urea requires more care in its
use than do the other two fertilizers. Urea is more likely to damage the plant if placed too close
to the roots, and it must be covered with soil. Moreover, farmers can see maize plants respond to
the application of CAN or AS within a shorter period of time than is the case when urea is
applied. However, farmers need to be aware of the additional cost they face using CAN or AS
rather than urea. Knowing this, likely farmers would be willing to buy urea and be a bit more
careful in using it, rather than buying the more expensive nitrogen of CAN or AS.
Where should limited amounts of fertilizer be applied on the field?
Most farmers in Malawi do not have homogeneous fields. Rather, the soil varies from
place to place in a field. Ant-hills, termites, or kaufiti (Striga) may make it difficult to grow
maize in some corners of the maize plot, while maize does well elsewhere. If a farmer only has a
limited amount of fertilizer, should he or she apply it to all parts of the field equally?
No, one should be selective in deciding which parts of the field receive fertilizer. The
best and the worst parts of the field should not receive fertilizer.
By the “best” parts of the field we mean the most fertile parts. Several areas of the
country have soils which are inherently very fertile - the heavier soils on the floodplains of the
Lakeshore and the Lower Shire Valley. Other areas of the country have small pockets of very
rich soil, particularly near dambos. Sometimes a field will have a patch of good soil which, even
without fertilizer, produces maize which is dark green in colour, full grown, and with large cobs.
This patch might have been where a cattle khola had been located or where a family formerly
lived. Whether such fertile areas are small patches within a field or full fields, farmers shouldn’t
put fertilizer on them. Such soils are not very responsive to fertilizer. The sale of the additional
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 19
maize which the fertilizer will provide from these patches will not be sufficient to pay for the
fertilizer applied to the maize there.
The “worst” parts of the field are those in which maize rarely does well. Adding
fertilizer to those parts usually will not change the situation and bring good maize harvests. The
reason those patches of the field do not provide any maize harvest likely is not because of poor
soil fertility, but some other problem. Kaufiti infestation may lead to no maize harvest. Termites
may destroy the crop year after year in that portion of the field. There may be some soil pest that
kills the maize. Waterlogging may prevent the crop from thriving. Fertilizer likely will not solve
the problems of poor production in these areas of the field. Do not waste fertilizer on them. It
would be better to grow a different crop than maize on these patches. Grain legumes –
groundnut, pigeonpea, soybean, Bambara groundnut, and others – particularly would be a good
alternative crop, as they reduce kaufiti and, if the residues are incorporated in the soil, will
improve the fertility and physical properties of such soils. Moreover the grain yield of these
legumes will likely exceed that of unfertilized maize on such sites.
As a general rule, apply fertilizer to those parts of the field where you can get a harvest
of maize, however small, without applying fertilizer. If you can get at least a small harvest of
maize off of the particular area of your field without fertilizer, you can quite confidently apply
fertilizer to that area and expect to get a higher yield. The fact that you get a harvest at all means
that maize can grow there – a pest or some other problem is not absolutely preventing maize
growth. Poor soil fertility is more than likely the reason the crop yield was small. If so, fertilizer
will address that problem.
What amount of fertilizer should be applied on the field?
The question then arises as to how a limited amount of fertilizer should be distributed
over the field. The farmer has two options:
a) Should one apply the fertilizer “thickly” over a small area of the field at the
recommended rate of application?, or
b) Should he or she spread the fertilizer “thinly” over a much larger area of the maize
field at a rate significantly less than the recommended rate?
The farmer should spread the fertilizer thinly at a rate lower than the recommended rate.
Recall two points from the discussion above. The first is the law of diminishing returns – every
additional kg of fertilizer you apply to a maize field will result in a slightly lower amount of
maize yield in response. Take a look back at Table 1. You get more maize for every kilogram of
fertilizer applied at lower rates of application than at higher rates.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 20
The second point is that the recommendations made in the two basic recommendations
maps are to be seen as maximums. Lower rates of fertilizer application than those indicated do
provide farmers with a good return. No one should see the recommendations as the only rate of
fertilizer to use. Lower rates make sense.
So, for example, if the recommendation for your area and production aim is 69:21:0+4S,
but you only have enough fertilizer to apply that amount to half of the area of your field on
which it is worthwhile to apply fertilizer, it would be better to apply half of the recommended
rate over the entire area. Your maize yield at the end of the season will be higher by doing so
than if you applied the fertilizer to half of the field and nothing to the other half.
Of course, the farmer should use common sense in so doing. Below a certain level of
fertilizer application – not much less than a rate of one bag of fertilizer per hectare – it becomes
very difficult to apply the small amount of fertilizer evenly. In such cases, the farmer should
consider fertilizing those higher-potential parts of his or her field which require fertilizer at a
low, but manageable rate, and planting a different crop altogether on the remainder of the field
for which there is insufficient fertilizer. The best crop for the unfertilized portion would be one
of the grain legumes– groundnut, pigeonpea, soybean, or Bambara groundnut.
Use organic sources of fertility
Finally, inorganic fertilizer is not the only source of nutrients which farmers can apply to
their maize. Organic sources should be made use of if available. By organic sources, we mean
grain legume crop residues, khola manure of good quality, compost, and prunings from nitrogen
fixing shrubs and trees. Use of all of these will increase the nutrient content and improve the
physical condition of the soil.
However, you should pay attention to the quality of the organic material. You want
material that has a good amount of nitrogen and will rot relatively quickly when put in the soil.
Maize stover is not very suitable. It has very little nitrogen and does not rot very quickly.
The residues from nitrogen-fixing legumes are a much better choice of organic materials
to put in the soil. The farmer should consider putting into rotation with maize a crop of a grain
legume, such as groundnuts or soybean. Of all of the nitrogen-fixing legume crops in Malawi,
velvet bean (kalongonda) provides the greatest amount of nitrogen-rich residue for building the
fertility of the soil. If the kalongonda residues are incorporated into the soil after harvest, a
rotation with velvet bean will lead to higher maize yields.
Intercrops are also useful, although they will not give as much organic material as will
rotations. Pigeonpea, particularly, is a good intercrop with maize. Prunings from agro-forestry
plants should also be used. Discourage farmers from burning residues from leguminous crops.
In reality, they are burning good fertilizer when they do. It is foolish to do so.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 21
If the farmer uses an organic fertilizer, the farmer can reduce the amount of inorganic
fertilizer he or she uses on the maize crop. However, as organic sources vary so much in their
quality, it is difficult to provide a firm rule for farmers to use in judging how much less inorganic
fertilizer they might use in combination with organic source of soil fertility.
How to apply the proper amount of fertilizer to maize
An important consideration in applying fertilizer according to the recommendations is
how to be sure that one is putting on the proper amount to the maize. If you know the size of
your field in hectares or acres, it is relatively simple. The recommendations tell you how many
bags of urea and 23:21:0+4S are needed to fertilize a hectare of maize at the rate noted. If your
field is a quarter of hectare, you use a quarter of the amount noted. An acre is 0.4 of a hectare, so
if you know your field is an acre, use 0.4 of the quantity required for a hectare.
However, most farmers do not know how large their fields are in hectares or in acres.
While there are other ways to apply fertilizer, the most common fertilizer application method in
Malawi is dolloping – two small measures of fertilizer are applied into holes made near the base
on opposite sides of each planting station. Dolloping, if done with cups of the proper size, is a
precise way of applying the proper amount of fertilizer to maize.
For the method to be accurate, the farmer needs to plant his or her maize at the
recommended plant spacing, most commonly 75 cm between planting stations of three seeds
each on ridges spaced 90 cm apart. A spacing of 90 cm between planting stations of three seeds
each on ridges spaced 90 cm apart is also commonly used with taller maize varieties. Two
dollop cups are applied per station by most farmers. The dollop cups currently available in
Malawi which are appropriate for applying the basic fertilizer rates are #2, #5, and #8. The
number refers to the number of milliliters (ml) each contains. All Field Assistants should have at
least one set of these cups to show farmers.
Using these plant spacings, the basic fertilizer recommendations correspond to the
amounts of fertilizer applied per planting station shown in Table 4.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 22
• Table 4: Dollop fertilizer cup rates for recommended fertilizer
Basal fertilizer cup Top-dressing fertilizer cup
Fertilizer 23:21:0+4S (two applied per urea (two applied per
rate ml per station station) ml per station station)
75 cm x 90 cm x 3 seed planting density:
35:10:0+2S 3.9 ml (3.4g) #2 (level) 4.6 ml (3.4g) #2 (heaped)
69:21:0+4S 7.9 ml (6.7g) #5 (3/4 full) 9.2 ml (6.7g) #5 (scant)
92:21:0+4S 7.9 ml (6.7g) #5 (3/4 full) 13.8 ml (10.1g) #8 (scant)
90 cm x 90 cm x 3 seed planting density:
35:10:0+2S 4.7 ml (4.1g) #2 (heaped) 5.5 ml (4.1g) #2 (very heaped)
69:21:0+4S 9.4 ml (8.1g) #5 (scant) 11.0 ml (8.1g) #5 (heaped)
92:21:0+4S 9.4 ml (8.1g) #5 (scant) 16.5 ml (12.2g) #8 (heaped)
NB: “Scant” means not quite full.
As most farmers cannot find dollop cups for purchase in their markets, you should
encourage them to find substitute containers for the dollop cups. For example, the bottle top
from a soft drink or beer bottle will hold 4 ml when the fertilizer is leveled and 5 ml when
heaped. (A #5 cup level full holds 5 ml.) A Leopard matchbox will hold 24 ml when level and
30 ml when heaped with fertilizer. Other suitable containers may be available locally. Farmers
should experiment with other containers to determine their capacity in milliliters. They likely
will find some that are exactly the right volume for the fertilizer rates that should be applied to
Hybrid seed or local seed?
An important assumption of these recommendations is that the farmer is planting hybrid
maize seed. Most of the research underlying these recommendations was carried out using
hybrid maize seed, particularly MH17 and MH18. The returns to fertilizer use are highest when
it is applied to hybrid maize.
Even unfertilized, the most common hybrids significantly out-yield the local unimproved
maize most farmers plant. Under hybrid seed prices in the early 1990s, farmers were making a
smart decision to grow hybrid maize rather than local maize, even if they could not apply any
fertilizer to it. The cost of the seed would be covered by the cash the farmer received from the
sale of the additional maize which resulted simply from using the improved seed, even without
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Such is no longer the case. To plant a hectare to hybrid seed in 1998/99 cost about
MK 1250. This is a significant amount of money, an amount which many farmers will be unable
to afford without credit. More importantly, it is more than the amount of money the farmer will
earn selling the extra maize which the use of unfertilized hybrid seed yields.
For most farmers, if they cannot afford to use hybrid maize seed, they also will be unable
to afford fertilizer. However, there will be a few farmers who will not have access to hybrid
seed, but who do have some fertilizer which they would like to apply to their local maize. Even
though this practice cannot be recommended by extension agents, farmers will follow this
practice because they cannot afford the recommended optimal fertilizer practice of using hybrid
maize seed. When they come to extension agents for advice on how best to use fertilizer on their
maize crop when it is not hybrid, how should they be advised?
Not only does unfertilized local maize yield much less than unfertilized hybrid, local
maize does not respond as well to fertilizer as does hybrid maize. Research has shown that the
response of local maize typically is about two-thirds that of hybrid. Moreover, it is responsive
only at lower rates of fertilizer application (less than 69:21:0+4S), higher rates of fertilizer
providing little additional maize. If, as noted earlier, hybrid maize at 100 kg of fertilizer per
hectare provides 9.5 kg of additional maize for every kg of fertilizer applied, you should expect
that local maize will provide about 6 kg of grain for every kg of fertilizer. This lower response
means that lower rates of fertilizer should be applied to local maize than the area-specific rate
recommended for hybrid maize. The optimal application rate will be lower for local maize.
Given that the recommendation when growing hybrid maize for market sale is already
the lowest rate listed, fertilizer should not be used on local maize if one is growing it for the
market. You won’t be able to pay for the fertilizer with the extra maize the use of the fertilizer
For home consumption, a safe general rule would be to use no more fertilizer on local
maize than the next rate of fertilizer lower than the rate recommended for hybrid maize at that
site. So, for example, if, after taking into account all of the factors noted above which might
modify the basic recommendations, if the rate recommended for hybrid maize is 69:21:0+4S, you
could use 35:10:0+2S on the local maize.
Two other points should be made: First, farmers realize that all “local” maize is not the
same. Recycled hybrid maize will yield better than the average local maize when it is fertilized.
In stating this, it also must be clearly stated that recycling hybrid maize seed cannot be
recommended to farmers. New hybrid maize seed is the best seed to use if high yields are
desired. However, farmers do recycle hybrid seed, so we must be able to advise them on how to
do so to their own advantage. Research has shown that recycled hybrids MH17 and MH18 will
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 24
yield up to 80% of what new hybrid seed will yield when fertilized moderately. Typically,
average local maize yields are only 50% of the yields of new hybrid seed at similar fertilizer
levels. Consequently, given this yield advantage over local, the use of fertilizer on recycled
hybrid seed will be more profitable than if it is used on average local maize seed. If the farmer
cannot acquire hybrid seed, the farmer should be encouraged to recycle MH17 or MH18 hybrid
maize grain as seed.
Secondly, the Ministry of Agriculture and Irrigation is promoting the multiplication of
composite, open-pollinated maize varieties by smallholder farmers. They perform even better
than the recycled hybrid seed. They also are much less expensive than hybrid seed.
Consequently, fertilizer use on composite maize varieties should be strongly encouraged.
Regardless of the short term difficulties which we are now seeing in the use of fertilizer
by farmers, fertilizer use on maize must increase in the future. Malawi will be unable to feed
itself simply using the inherent fertility of its soil. Added nutrients must be supplied to the soil
to feed the crops. While organic sources of fertility – rotations, intercropping, agro-forestry
methods – must be used, it is unlikely that they will be sufficient in themselves to provide the
nutrients necessary to provide the additional maize harvest required by the nation. Inorganic
fertilizer must be part of the future of agriculture for food security in Malawi.
This manual provides Field Assistants with guidance on how to offer advice to farmers
so that they can make profitably use fertilizer on maize in the current economic conditions.
Clearly fertilized maize cannot presently be seen as an important commercial activity. There are
many other agricultural activities which will provide farming households with more cash.
However, fertilizing maize for home consumption continues to be a viable, worthwhile use of
household resources, so long as the fertilizer can be purchased using cash resources within the
In this regard, it is hoped that this document will enable you to confidently decide with
farmers what fertilization strategy they should follow with their maize. Additionally, the simple
guidelines provided should allow them to effectively make use of whatever fertilizer they can
acquire for use on maize. Ideally this manual will contribute towards achieving the aim towards
which it is directed – to enhance the welfare of the farmers with whom you work and the food
security of the nation of Malawi as a whole.
The other common maize hybrids like NSCM41, MH12, and MH16 will not perform as well as MH17 and
MH18 when recycled due to differences between them in the manner in which they were bred.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 25
Appendix – Pattern of area-specific fertilizer recommendations within ADDs
The smallest area to which a recommendation applies is the EPA, but some EPAs are
quite diverse. Consequently here the recommendation zone pattern in each ADD is briefly
discussed in turn to highlight any smaller areas of the EPAs within the ADD where the EPA-
level recommendations may not be wholly appropriate. Please refer to Figure 3 and Figure 4, as
well as to Table 2, as you read.
Three sets of recommendations apply for KRADD – one of somewhat higher rates for the
mid-altitude plateau of Chitipa RDP, a second with lower rates for Karonga RDP, and an
intermediate recommendation for Misuku EPA in the high-rainfall Misuku Hills.
Three recommendation decision trees apply for MZADD – lowest rates apply in Nkhata
Bay and Chintheche along the lakeshore, intermediate rates apply in the northern hill zone of
Nchenachena, Muhuju, and Mpamba along the lakeshore, and the highest rates in the plains of
Mzimba and Nkhamanga to the west.
The most complex area of MZADD is along the Rift Valley in Nkhata Bay RDP,
particularly in Nkhata Bay and Chintheche EPAs. At higher elevation sites in these areas, the
higher rates for the neighboring upland zone should apply.
A single set of recommendations applies to Kasungu ADD, appropriate for all areas.
A single set of recommendations applies to Lilongwe ADD, appropriate for all areas.
Two sets of recommendations apply to Salima ADD. A set of intermediate rate
recommendations applies to north Nkhotakota, adjoining the areas of the Nkhata Bay and
Chintheche lakeshore to which even lower rates apply. The rest of the ADD receives the highest
rates of application for each production aim – 35:10:0+2S for market sale production and
92:21:0+4S for home consumption.
It is expected that rainfed cropping of maize in SLADD will not be taking place in the
fertile, but typically waterlogged dambos of the lakeshore. In such areas, generally used for dry
season, dimba cropping, lower rates of fertilizer should be used. The recommendations given here
are for those drier, less fertile soils in which maize is grown during the rains.
Two sets of recommendations apply to Machinga ADD, recommendations which only
differ in the rates which apply when growing maize for home consumption. 69:21:0+4S is
recommended in fertile, alluvial areas or in areas where rainfall is more erratic. The highest rate of
92:21:0+4S applies elsewhere.
As with SLADD, it is expected that rainfed cropping of maize in MADD will not be
taking place in the fertile, but typically waterlogged dambos of the Mangochi lakeshore. In such
areas, lower rates of fertilizer should be used.
Two sets of recommendations apply to Blantyre ADD, recommendations which only
differ in the rates which apply when growing maize for home consumption. 69:21:0+4S is
recommended in Mwanza RDP and Lirangwe EPA, an area where rainfall is not as reliable as on
the Shire Highlands or further to the east. The highest rate of 92:21:0+4S applies in those areas.
AREA-SPECIFIC FERTILIZER RECOMMENDATIONS FOR MAIZE - PAGE 26
Shire Valley ADD
A single recommendation decision tree applies to SVADD. Fertilizer use in the ADD is a
risky investment for farmers to make given the variable rainfall from year to year – either drought
or heavy rains – and the lack of an economic response to fertilizer on the rich alluvial soils in the
valley. Consequently very low rates of fertilizer, if any, are recommended.
However this set of recommendations is not necessarily appropriate for the small upland
areas of the ADD – Chididi, Lulwe, northern Chapananga, and the area to the east of Kapichira
Falls. The appropriate recommendations for these less fertile upland zones would be that of the
Mwanza area of BLADD, which has comparable agro-ecological conditions: 35:10:0+2S when
growing maize for market sale, and 69:21:0+4S when producing for home consumption.