The Sunday Mail
Peter Gambara
Since Government announced the launch of the Command Agriculture Programme, many farmers have been wondering if they will be able to attain the desired yield levels.
In this article, I will try to provide as much facts and figures as possible to enable farmers to plan for high yield levels.
Government wants to contract 2 000 farmers, who will each grow 200 hectares of maize and are expected to get at least five tonnes per hectare each.
The total area to be contracted, therefore, is 400 000ha. Government plans to avail US$1 250 per ha for 400 000ha. This will bring the total cost to US$500 million.
It will cost roughly US$800 to produce a hectare of maize.
However, Government has indicated it is targeting farmers with irrigation facilities and, therefore, the extra US$450 per hectare could be budgeted towards meeting the cost of water from Zinwa and electricity charges to pump the water.
If Government is going to avail US$1 250 per hectare and expect those farmers to produce at least five tonnes per hectare, it means it will cost US$250 to produce a tonne (US$1 250/5t/ha).
Since all farmers are expected to deliver their maize to the Grain Marketing Board for repayment of the loan, it is safe to say the maize will be valued at US$390 per tonne (GMB Producer Price).
If a farmer is loaned US$1 250/ha, it means the farmer should pay back US$1 425 (including 14 percent interest), and should deliver 3,65 tonnes per hectare to repay the loan (US$1 425/US$390 per tonne).
If a farmer harvests five tonnes per hectare, he/she will remain with 1,35 tonnes to sell per hectare or US$525 worth of maize per hectare (a 36,84 percent return on amount invested).
Farmers who get yields higher than five tonnes per hectare will enjoy a higher return.
It costs about US$70 per hectare to hire a tractor to either plough or disc one’s land. Depending on the size, efficiency and age of the tractor, it takes 25-30 litres of diesel per hectare to plough a piece of land and 15-20 litres of diesel to disc the same piece of land.
An 80-horse power tractor will use less diesel than, say, a 110hp tractor.
A brand new tractor or one that is, say, five-years-old but maintained regularly, is more efficient than an old tractor that is smoking and leaking oil everywhere.
A three-dish plough requires at least a 75hp tractor (3x25hp per disc).
Therefore, using a 100hp tractor to draw a three-dish plough is inefficient as the extra 25hp will simply go to waste.
Ploughing is much slower than simply discing as the ploughing goes deeper than discing. It is difficult to plough or disc dry land, especially on sandy soils that tend to develop a hard pan easily. Those on red clay soils can still plough their land at this time of the year, but the ploughing normally results in lots of clods that will require another operation to break them to achieve a smooth tilth.
Depending on how many operations a farmer has to perform to get the right tilth, land preparation costs will vary.
Whilst some farmers own tractors and implements, others are not so lucky and have to hire the same for land preparation.
A lot of companies now offer hiring facilities for land preparation in different farming areas. Neighbouring farmers also sometimes assist each other with tractors and equipment.
An 80hp tractor with a three-disc plough will require 25-30 litres per hectare and it will take approximately three hours to plough a hectare.
A farmer requires 25kg of seed to plant a hectare.
However, there is now more realisation that if rainfall and fertilisers are not likely to be limiting, a farmer should go for a higher plant population.
Traditionally, farmers were told to plant maize at a spacing of 90cmx30cm, bringing the plant population to 37 000 plants per ha.
Nowadays, some seed houses sell 50 000-kernel pockets of seed and this should give a plant population of about 50 000 plants per ha.
Some farmers now reduce the spacing to 75cm between-rows and 20cm in-row, to give a plant population of at least 66 000 plants per ha.
Small-kernelled seed will give more plants per hectare than large-kernelled seed.
This is one reason why some farmers, especially those who use planters, prefer small-kernelled seed as these cover either a bigger area or give a higher plant population per ha.
A plant population of between 50 000 and 66 000 plants/ha can easily yield eight to 10 tonnes/ha.
The amount of fertiliser a farmer uses at planting and at top-dressing stage has a large bearing on the yield.
Those farmers in more rainfall dependent areas (Natural Regions II and III) will achieve higher yields if they apply higher (heavier) fertiliser rates, than those who use lower rates in drier areas, eg NR III and IV.
A farmer who uses 400kg (8x50kg) per ha is more likely to have a better crop yield than one who uses 250kg/ha (5x50kg). See the table below for general guidelines.
The method of fertiliser application also matters.
Use of a planter is more efficient than hand planting, as the planter will place the seed and fertiliser at uniform depths and space.
Farmers who grow large areas of maize will use a vicon spreader to apply top-dressing unlike small-scale farmers who will place fertiliser per plant using a fertiliser cup or just dropping it by hand.
However, it is important to stress that a farmer should only use higher fertiliser rates when the moisture is guaranteed, hence Government’s insistence on selecting farmers with irrigation facilities.
Should they experience extended dry spells, farmers can supplement the natural rains by irrigating.
Recommended irrigation intervals range from four to six days depending on the crop stage and soil type. Critical moisture crop stages include germination, flowering and grain filling.
If enough moisture is available, maize will normally germinate in about seven days.
Some farmers get poor yields because of poor germination. If a farmer has irrigation facilities, he/she should ensure the field has enough moisture for the seed to germinate.
Some soils have a capping effect and if it dries before the seed germinates, the germinating seed will fail to penetrate the top soil and will simply curl back into the soil and rot.
It is essential, therefore, that the soil has enough moisture within the seven days that the seed is germinating.
Farmers who grow big areas are encouraged to use herbicides to control weeds. Maize should be kept weed-free for the first six to eight weeks for maximum yields.
Weeds compete with maize for both nutrients and moisture. The key in using herbicides is knowing the weed spectrum on your land.
The most common weeds are broadleaf, annual grasses, perennial grasses, yellow and purple nutsedge and Shamva grass. Some of the most common herbicides used in maize include Atrazine, which is a selective pre or post- emergent herbicide that controls most grasses and broadleaves.
However, it has a long residual effect and should not be used where a broadleaf will be planted in the same rotation. Dual is also used quite widely, especially on clay soils.
There are a wide range of herbicides available on the market and farmers should approach agronomists for the best advice.
Herbicides are most effective when they are applied under moist conditions.
Hand weeding can be very slow and by the time one attends to the 200th hectare, the weeds might have overgrown and started affecting the crop.
Once weeds have overgrown, most farm labourers – especially seasonal ones – will shun weeding as it slows them down. Herbicides should be applied before a certain stage, usually at two to three-leaf stage.
If one delays too much, the herbicide will not be able to control the weeds.
For those farmers who grow maize on the same piece of land, year after year, there is a risk of maize stalk borer damaging the crop as it tends to build up in the soil. These farmers should apply chemicals onto the funnel of the maize before tasselling to control stock borer damage.
A commonly used chemical is Dipterex, which is sprinkled onto the funnel of the maize when the crop is at knee height.
Weather experts predict that the 2016/17 summer season might be affected by the La Nina effect, which is the opposite of the El Nino effect we experienced last season.
The La Nino effect will result in very wet conditions from December to February with the result that most crops, especially maize, will turn yellowish.
This yellowing is caused by leaching that is brought about by heavy rains.
Maize is more susceptible to leaching where the crop did not receive enough basal fertilisers and if the crop is still young. Farmers should, therefore, strive to plant early and discourage water accumulating in their lands as much as possible.
Rain will accumulate on the land if the drainage is bad and normally, this happens when there are insufficient conservation works like contours and storm drains.
Unfortunately, a lot of farmers continue to plough up their lands without any conservation works.
Farmers should approach Agritex extension workers to have their conservation methods checked ahead of the summer season.
Mr Peter Gambara is an agronomist based in Harare. He wrote this article for The Sunday Mail
