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Farming in conditions of low rainfall

09 Sep, 2018 - 00:09 0 Views
Farming in conditions of low rainfall

The Sunday Mail

Peter Gambara
Weather experts, both regionally and nationally, have made their predictions and we should expect normal to below normal rain in the coming season.

The consensus forecast produced by the Southern African Regional Climate Outlook Forum (SARCOF) held in Lusaka, Zambia recently, shows most of the 16 Sadc countries are likely to receive normal to below normal rainfall during the first half period from October 2018 to December 2018. The second half period from January to March 2019 is not showing any improvement.

Therefore, the question that follows is, how can local farmers prepare for such a season?

Pre-season preparations

A below normal rainfall season means the total amount of rainfall is below what is normally received in a “normal year”.

However, in some situations, it also means the spread of the season is not even, the first half might have enough rainfall, whilst the second half will be below normal. A season where we experience unusually long dry spells is also not good for the crops and might negatively affect the plants.

The best way to prepare for a below normal season is for a farmer to be ready to plant early. We expect our first effective rainfall around end of October to beginning of November.

A farmer is therefore well prepared, if he or she can plant with those first effective rains.

How can a farmer be ready?

Firstly, farmers should be able to do land preparation in advance, so that come that time, they will be able to move in and plant with minimum tillage operations.

Agriculture extension officers normally encourage farmers to practise “winter ploughing”.

Essentially, farmers are encouraged to deep plough their lands whilst they are still moist, immediately after the end of the rains between May and July.

Trying to plough most lands, especially the predominantly sandy soils, is difficult after August since they will have formed a hard pan. However, those with red clay soils can still be able to plough, although the result is often many big clods that will need to be broken further with a roller.

It is also essential that farmers buy their seed, fertilizers and chemicals in advance and stock them in preparation for the summer season. Last minute rushes to purchase inputs are not very wise as some inputs might be in short supply then.

The lessons from last season where fertilizers were in short supply between November and January should remind farmers of the need to secure inputs early.

Crop and variety selection

In the face of an impending drought season, farmers are encouraged to plant short season varieties rather than long maturing varieties.

A shorter maturity variety not only matures quicker, but also requires less rainfall to reach maturity, as compared to a long-season variety. During the 2016-17 summer season, when the country experienced a good rainfall season, the long season varieties like SC727 did exceptionally well, such that the next season, almost every farmer wanted to grow it.

Such varieties are only recommended for those farmers with supplementary irrigation facilities. During a drought year (below normal rainfall), the goal shifts from targeting to get 10 tonnes and above harvest, to salvaging something reasonable from the field.

Only the “clever farmer”, who buys his or her inputs in advance, will be able to secure his or her desired varieties. Farmers, especially those in marginal areas, are also encouraged to diversify their crops to include drought tolerant small cereal grains like sorghum and millets.

These can better withstand drought conditions and will usually yield something under drought conditions, compared to maize. Improved early maturing varieties of millet and sorghum are now available on the market.

Farmers should also grow sugar beans, sweet potatoes, and cassava as these will become handy in drought situations.

Agronomic practices

Given the same inputs at the same time, it is highly likely that two different farmers will get different yields.

This is mostly because of crop management or agronomic practices. A poorly prepared land will delay crop germination or prevent the seeds from germinating.

Therefore, the first strategy is always to make sure the land has been prepared well and that the tilth is smooth and conducive to crop germination. The method of planting also has a bearing on the germination. Seeds that are placed too deep into the soil will find it difficult to germinate.

Most small-scale farmers open up planting furrows using a plough and sometimes those furrows are just too deep. A maize seed should not be planted more than 5 cm deep.

A season like this requires precision in everything that a farmer does, supervise your operations and ensure they have been done properly. Most small-scale farmers believe in planting maize seed without fertiliser and then come later to incorporate the basal fertilizer.

A crop that is planted without basal fertiliser will emerge from the soil very weak, it is like a child with kwashiorkor, and it will fail to thrive. After a crop has germinated, the next steps relate to how a farmer manages the crop until it reaches maturity.

A “clever farmer’, who has all the inputs at his or her disposal, will be ready to apply top dressing fertilizer once they get some rainfall. As highlighted above, a below normal season might mean intermittent rain showers every now and then.

Whilst the recommendation to most farmers is to split apply top dressing fertilisers at two, four and six week stages, in an abnormal season, the clever farmer will apply some top dressing fertiliser anytime he or she gets some moisture towards or around the two, four and six week stages.

It is common to hear some farmers mourn that the rains were patchy, when their neighbours have a thriving crop because they adopted that strategy. It is also very critical that farmers try as much as possible to follow fortnightly weather forecasts on their mobile phones or on radio and TV.

These will be helpful in determining when to apply top dressing fertilisers.

Top dressing fertilizers should never be applied under dry conditions. Unlike before, the most readily available form of top dressing now is Urea and some of the Urea that is available on the market has been made into granular form and it looks as white as the usual Ammonium Nitrate.

Many farmers have therefore been tempted to just place it on top of the soil next to the plants as they do with AN.

Urea that is placed like that risks just volatising into the air as ammonia gas. This is especially true if it remains on the soils surface for extended periods during warm and dry weather. One of our worst enemies in growing crops is weeds infestation.

Weeds compete with the crops for both moisture and nutrients and the more a farmer delays to remove or control them, the more moisture and nutrients that are taken by the weeds. The recommendation is that fields should be weed free, at least for the first eight weeks after germination.

The habit among some small-scale farmers is to plant more areas than they can effectively weed with their family labour.

With these free agricultural inputs from Government, some farmers never stop to think how they will eventually control the weeds and only realise it when it is too late and have planted too big areas.

Days of farmers struggling to weed many fields are now outdated, farmers should now move on to use herbicides. The key to using herbicides lies in knowing your weeds, different herbicides act on different weeds. Do not just copy others without first establishing the type of weeds you want to eliminate.

It is also important that some kind of synchronisation be done when planting crops.

I have seen farmers, who got the Glyphosate herbicide from the Command Agriculture programme, failing to control the grasses that they intend to control simply because they have failed to synchronize their operations. They kept concentrating on planting, forgetting that Glyphosate is a non-selective herbicide and by the time they wanted to go back and spray it on the planted crop, the maize had already started germinating and the herbicide would kill the maize. Therefore, farmers please plan your activities.

One reason why such things happen is also that farmers do not have adequate equipment to use on their operations.

They have to borrow a boom sprayer from the farmer next door. However, that next-door farmer will also want to spray his or her crop whenever there is some moisture.

Most herbicides require some moisture to be effective. Therefore, farmers should strive to own their own equipment. If you cannot afford a boom sprayer that costs about $4 000, buy knapsack sprayers that cost about $25 each.

Three workers with knapsack sprayers are able to spray a herbicide on a hectare in a day.

Each worker should be able to spray a drum (200 litres) or 14 X 15 litre knapsack sprayers in an 8-hour day shift.

Water conservation strategies

When water is little, it is common knowledge that it should be conserved and utilized productively.

Do not allow water to run off from the fields, where you want it to irrigate and grow your crops. Firstly, make sure all the conservation works are in place. Most lands were last pegged for storm drains and contours long back.

The absence of these storm drains and contours will result in heavy rainfall running off the fields, sometimes causing massive erosion. I have seen many farmers who try to put contours when it is already too late and erosion has already set in.

As water runs off the fields, it washes the nutrients with it and this deprive crops of some of the nutrients that you will have applied. Where a farmer claims to have applied say 400 kg of fertilizer per hectare, maybe half of that finds its way into the rivers and water bodies after being washed away.

Farmers do not normally grow crops on ridges, but for crops like tobacco that are grown on ridges, it also makes sense to use tied ridges. This is a practice where farmers place some raised ties between ridges, to trap water between the ridges, and give it more time to sink into the soil.

That improves the water or moisture availability to the crop. In the absence of these tied ridges, water will simply run off the fields.

Remember, tobacco ridges are normally made at a slope, to allow for good drainage and therefore it is easy for the water to run off down the slope to the edge of the field and into the drainage systems and rivers.

Pest control

We recently have experienced an outbreak of Fall Army Worm (FAW) in Zimbabwe and if left unchecked, this pest can cause massive grain loss to the farmer.

There is a wide variety of chemicals that are available on the market that can control FAW, however, chemical control is expensive and some farmers fail to buy effective chemicals on time. The recommendation is for farmers to learn how to scout for FAW, move in, and crush the eggs as soon as they are observed. Farmers can also practice some biological ways of controlling FAW.

Biological control methods include the growing of weeds that produce a lot of flowers around the maize fields or in-between maize fields. The nectar produced by the flowers will attract predators of the FAW.

Farmers are also encouraged to grow Napier grass around the maize fields.

The Napier grass, being a grass, will attract the FAW to lay its eggs on it. However, it does not allow larvae to develop on it due to its poor nutrition, and therefore very few caterpillars will survive. To reduce FAW attack, farmers should shun late planting.

The late-planted crop (December and January) tends to be attacked more than the November or October planted crop.

Again, farmers should now avoid staggering their crops if planting in the same area.

If you stagger your maize plantings, you are continuing to provide the favoured food for the FAW and besides, one crop breeds the FAW for the next crop. The pest will be very grateful for the continued environment on your farm. Besides the FAW, farmers should also pay attention to the usual stock borer that has always attacked our crops towards the grain filling stage.

A clever farmer will always work hand in glove with his or her extension worker or officer. When not sure, consult your extension agents, they provide a free service to farmers.

Good luck with the season ahead.

Peter Gambara is an agricultural economist and consultant based in Harare. He wrote this article for The Sunday Mail.


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