54 research outputs found
A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions
Conservation agriculture involves reduced tillage, permanent soil cover and crop rotations to enhance soil fertility and to supply food from a dwindling land resource. Recently, conservation agriculture has been promoted in Southern Africa, mainly for maize-based farming systems. However, maize yields under rain-fed conditions are often variable. There is therefore a need to identify factors that influence crop yield under conservation agriculture and rain-fed conditions. Here, we studied maize grain yield data from experiments lasting 5 years and more under rain-fed conditions. We assessed the effect of long-term tillage and residue retention on maize grain yield under contrasting soil textures, nitrogen input and climate. Yield variability was measured by stability analysis. Our results show an increase in maize yield over time with conservation agriculture practices that include rotation and high input use in low rainfall areas. But we observed no difference in system stability under those conditions. We observed a strong relationship between maize grain yield and annual rainfall. Our meta-analysis gave the following findings: (1) 92% of the data show that mulch cover in high rainfall areas leads to lower yields due to waterlogging; (2) 85% of data show that soil texture is important in the temporal development of conservation agriculture effects, improved yields are likely on well-drained soils; (3) 73% of the data show that conservation agriculture practices require high inputs especially N for improved yield; (4) 63% of data show that increased yields are obtained with rotation but calculations often do not include the variations in rainfall within and between seasons; (5) 56% of the data show that reduced tillage with no mulch cover leads to lower yields in semi-arid areas; and (6) when adequate fertiliser is available, rainfall is the most important determinant of yield in southern Africa. It is clear from our results that conservation agriculture needs to be targeted and adapted to specific biophysical conditions for improved impact
BIOMASS YIELD OF CROTALARIA JUNCEA AFTER THINNING AND AT VARIED SOWING DENSITIES IN THE COASTAL PLATEAU OF PIAUĂ STATE, BRAZIL
Modern High-Yielding Maize, Wheat and Soybean Cultivars in Response to Gypsum and Lime Application on No-Till Oxisol
EFEITOS DA PASTAGEM DE AZEVĂM SOB DOIS PREPAROS DE SOLO, NO DESEMPENHO EM RECRIA E PESO Ă MONTA DE BORREGAS IDEAL
Isotermas de dessorção das sementes de nabo forrageiro obtidas pelos métodos dinùmico e eståtico
Variação temporal do intervalo hĂdrico Ăłtimo de um latossolo vermelho distrofĂ©rrico sob sistemas de plantio direto
Soil organic matter pools in a tropical savanna under agroforestry system in Northeastern Brazil
A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions
- âŠ