Farm­ing in con­di­tions of low rain­fall

The Sunday Mail (Zimbabwe) - - ANALYSIS - Peter Gam­bara ◆ Peter Gam­bara is an agri­cul­tural econ­o­mist and con­sul­tant based in Harare. He wrote this ar­ti­cle for The Sun­day Mail.

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.

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