SOJABONE – ’N OUTOMATIESE KEUSE VIR ’N WISSELBOUSTELSEL

SOYBEANS – AN AUTOMATIC

CHOICE FOR A ROTATION SYSTEM

Geskryf deur / Written by

w

INHOUDSOPOGAWE / INDEX

SOJABONE – ’N OUTOMATIESE KEUSE VIR ’N WISSELBOUSTELSEL

D ie 2015/2016-produksieseisoen was vir die meeste produsente ‘n vyfster riller. Veral die westelike produksiegebiede het buitengewone weersomstandighede beleef waarvan droogte en hitte die ergste was. Sou die langtermynvoorspellings van die

aardverwarmingsprofete waar word, dan gaan die klimaat baie meer wispelturig raak. Voeg hierby die graanmarkte wat ook wipplank ry, dan is dit duidelik dat ‘n produsent sy risiko sal moet versprei. Wisselbou is die logiese keuse vir ‘n graanprodusent – met sojabone as een van die beste kandidate saam met mielies.

HOEKOM ’N WISSELBOUSTELSEL?

Voorspelbaarheid binne landbou is, om die minste te sê, baie moeilik indien nie heelte-mal onmoontlik nie. Onder sulke omstandighede is dit gerade om risiko so ver prak-ties moontlik te versprei. ‘n Gesonde wisselboustelsel met sojabone as een van die

komponente is ‘n uitstekende metode om risiko te beperk.

In die hedendaagse landbou is dit noodsaaklik om die winsgewendheid van enige boerdery-stelsel baie goed te evalueer. Prysverhoudings tussen gewasse word dikwels as kriteria ge bruik om te bepaal watter gewasse aangeplant gaan word. ‘n Wesentlike probleem met so ‘n benadering is dat pryse van verskillende gewasse dramaties gedurende ‘n seisoen kan wissel na gelang van weersomstandighede en internasionale voorrade. Die 2015/2016-seisoen was ‘n sprekende voorbeeld hiervan. Mieliepryse het die seisoen alle verwagtings oortref, wat nie die geval was met sojabone nie. Dit is egter hoogs onwaarskynlik dat dieselfde prysverhoudings vir ‘n volgende seisoen sal geld. Prysverhoudings is slegs een van die oorwegings wat oorweeg behoort te word in die keuse van ‘n wisselboustelsel.

Die winsgewendheid van enige gewas is ook ‘n funksie van opbrengs. Die 2015/2016-produksieseisoen, het, wat opbrengsverhoudings be-tref, vreemde resultate opgelewer. Mielie-op brengste in die droogtegeteisterde westelike produksiegebiede, het ‘n opbrengsslagting beleef. Al hoewel sojabone se opbrengs ook nadelig geaffekteer is, was hierdie gewas in staat om oor ‘n langer periode te blom en dus steeds op-brengs te lewer waar ander gewasse misluk het. Voeg hierby die vermoë van sojabone om diep vog te benut, dan word die risikoprofi el van die gewas heelwat beter as dié van ander mededingers.

Die prys van ‘n gewas alleen bepaal nie wins nie. In dié verband het sojabone ‘n beduidende voordeel. Stikstof (N)-bemesting kan vir alle prak-tiese doel eindes buite rekening gelaat word in die produksiebegroting. In die meeste produk-siegebiede sal sojaboon produksie koste ook laer wees as dié van mielies.

4

IS DAAR VOORDELE OM ’N WISSELBOUSTELSEL TE VOLG?

Daar kan ‘n wye verskeidenheid van voordele genoem word, soos onkruidbeheer en beter benutting van werktuie, maar vir die doel van die skrywe sal slegs enkeles genoem word.

Gewasse verskil in hul vermoë om by bepaalde klimaatsomstandighede aan te pas. Mielies het ‘n kort reproduktiewe fase wat deur baie faktore, onder meer temperatuur, bepaal word. In die geval

van onbepaalde groeiwyse sojaboonkultivars, kan hierdie kritiese periode maklik drie keer langer gerek word. Voeg hierby diep vogonttrekking, dan is dit duidelik dat ‘n produsent se risiko -

pro fi el verbeter.

Verskeie plaaslike proewe, maar ook in die buiteland, het aangedui dat mielies wat ná soja-bone volg, ‘n opbrengssprong van minstens 10% lewer, in vergelyking met monokultuur-mielies. Hierdie opbrengssprong (wat meestal meer as 10% is) word selde in berekening gebring waar die betalendheid van gewasse met mekaar vergelyk word.

Waar bewaringsbewerking toegepas word, is dit noodsaaklik dat daar wegbeweeg word van enige monokultuurstelsel. Hoe meer gewasse mekaar opvolg, hoe beter. Sojabone skakel besonder goed by so ‘n stelsel in omdat dit ‘n baie produktiewe peulgewas verteenwoordig.

FREKWENSIE VAN GEWASOPVOLGING

Sou suiwer akkerboupraktyke in ag geneem word, dan word daar ver-kies dat sojabone elke derde jaar op ‘n bepaalde land verbou word. Ekonomiese faktore soos pryse van kompeterende gewasse kan hier-

die verhouding beïn vloed. Daar is egter geen plaasvervanger vir ‘n gesonde gewasopvolgstelsel wat oor tyd volgehou word nie.

‘‘...mielies wat ná soja bone volg, lewer ‘n opbrengssprong

van minstens 10% , in vergelyking met

monokultuur mielies.’’

5

SOYBEANS – AN AUTOMATIC CHOICE FOR A ROTATION SYSTEM

The 2015/2016 production season was horrendous for most producers. The western production areas experienced extraordinary weather conditions. Drought and heat were the worst of those conditions. If the long-term expectations of the global warm-

ing prophets were to be realised, our climate will become increasingly fi ckle. Add the insta-bility of the grain markets and it becomes clear that producers will have to distribute risks. Crop rotation systems is the logical choice for grain producers – and soybeans is one of the best candidates for rotation with maize.

WHY A CROP ROTATION SYSTEM?

Predictability within agriculture is extremely diffi cult, if not totally impossible. In these circumstances it is prudent to distribute risk as much as possible. A healthy crop rota-tion system with soybeans as one of the components, is an excellent method to

limit risk.

Within current agricultural circumstances, it is essential to properly evaluate the profi tability of any farming system. Price ratios relating to various crops are often used as criteria to determine the types of crops to be planted. One material problem with such an approach is the possibility of dramatic price variations within a single season, depending on weather conditions and international stocks. The 2015/2016 season was a good example. Maize prices exceeded all expectations, which was not the case with soybeans. However, it is high-ly unlikely that the same price ratios would apply during the next season. Price ratios are only one of the considerations when determining the components of a crop rota tion system.

The profi tability of any crop also depends on yield. The 2015/2016 production season ren-dered strange results in terms of yield ratios. Maize yields in the drought-stricken western production areas suffered severe blows. Although soybean yields were affected negatively too, the crop could fl ower over a longer period and render yields where other crops failed. Add the soybean ability to utilise deep moisture and the risk profi le of the crop improves signifi cantly compared to competitors.

    Prices relating to a crop do not solely determine profi t. In this regard, soy-

beans provide a signifi cant benefi t. For all practical considerations, nitrogen (N) fertilisation may be left out of the production budget

equation. In addition soybean production costs in most production areas are considerably lower than those of maize.

gbeans provide a

nitrogen (N)equation.

areas a

7

WHAT ARE THE BENEFITS OF A CROP ROTATION SYSTEM, IF ANY?

There are a number of benefi ts, including weed control and better utilisation of implements, but for the purposes of this document, only a few will be mentioned.

Crops vary in terms of ability to adapt to different climatic conditions. Maize has a short reproductive phase, determined by many factors including temperature. The indeterminate growth of soybean

cultivars could mean an increase of almost three times this period. Add the deep moisture utilisation and it becomes clear that the risk profi le improves for the producer.

Various local and international trials showed that maize planted after soybeans, show a yield increase of at least 10% compared with monoculture yields. The jump (mostly more than 10%), is seldom taken into account when comparing the profi tability of various crops.

Where conservation agriculture is practised, it is essential to move away from any monoculture system. The more consecutive crops, the better. Soybeans fi t such a system particularly well, because it is a very productive legume crop.

FREQUENCY OF CROP ROTATION

From an agronomic point of view, it is preferable to plant soybeans every third year in a particular fi eld. Economic factors such as prices of compet-ing crops may infl uence this ratio. However, there is no substitute for a

healthy crop rotation system that is maintained over time.

‘...maize planted after soybeans, show a yield

increase of at least 10% compared with monoculture yields.’

8