Tillage effects on maize yield, rooting depth and soil water content on sandy soils in Zimbabwe
1993
Vogel, H. (Dept. of Agricultural , Technical and Extension Services, Harare (Zimbabwe). Institute of Agricultural Engineering)
Maize (Zea mays L.) yields from granitic soils, cultivated by different tillage techniques, were measured over a period of three rainy seasons in the subhumid and semi-arid regions of Zimbabwe. Results revealed that besides tillage, seasonal rainfall pattern and the year site interaction had highly significant effects on maize production. In addition, topographical and soil profile characteristics were highly related to maize yield. Out of five tillage systems, the no-till tied ridging technique resulted in highest grain yield in the subhumid region but yields fluctuated strongly and were rather poor in the semi-arid zone. This was mainly due to lower top soil water contents in the elevated ridges which prevented waterlogging in the subhumid region but caused emergence and established problems in the semi-arid region. In the semi-arid region the mulch ripping technique was superior to the other treatments in drought years if there were enough crop residues left on the soil surface from the previous season. Where this was not the case, mouldboard ploughing and clean reaping yielded best. Hoeing-out (hand hoeing), practised by subsistence farmers short of draught power, performed consistently well in the subhumid region, but yielded inconsistently and rather poorly compared to the other treatments in the semi-arid region
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