Papers by hupenyu mupambwa
Abstract
There is substantial evidence that cover crops increase soil fertility and pl... more Abstract
There is substantial evidence that cover crops increase soil fertility and plant nutrition but the few studies concerning soil physical properties are conflicting. This study determined the effects of monocultures of vetch (Vicia dasycarpa L.), lupin (Lupinus angustifolius L.), oats (Avena sativa L.) and bicultures of oats and vetch and a weedy fallow on the strength and water conservation properties of a hardsetting Oakleaf soil. Oats monoculture lowered the soil strength by 48.5%, whilst vetch and lupin increased soil strength by 43% and 31%, respectively, relative to the control. Bicultures decreased soil strength as the proportion of oats increased. Oats monoculture increased cumulative water infiltration relative to the control. Bicultures increased the water final infiltration rate by 105–163% compared to the control. Plant available water increased by 24–28% compared to the weedy fallow under monocultures. However, no significant differences were observed on plant available water after two rotations with bicultures compared to the weedy fallow. We concluded that oats monoculture reduced the strength and improved water conservation properties of the hardsetting soil but vetch and lupin monoculture worsened the deleterious effects of the hardsetting phenomenon.
Abstract
Mono- and biculture cropping systems are thought to affect aggregate stability ... more Abstract
Mono- and biculture cropping systems are thought to affect aggregate stability by influencing soil polysaccharides but the exact relationship is uncertain. The objective of this study was to determine the effects of cover cropping systems on polysaccharides and aggregate stability in an Oakleaf soil. Two experiments involving a cereal, two legumes and a weedy control, either in mono- or biculture, were done. The crops were oat (Avena sativa L.), vetch (Vicia dasycarpa L.) and lupin (Lupinus angustifolius L.). All cover crops in both cropping systems increased soil polysaccharides. Cover crops in both systems improved aggregation either by increasing macroaggregates and/or lowering the percentage of the 0.25–0.106 mm aggregate fraction size. The mean weight diameter increased under the mono- but not biculture system. The hot-water extractable polysaccharides fraction was actively involved in aggregation in the Oakleaf soil. The correlation between hot-water extractable polysaccharides and the mean weight diameter was negative (r= −0.55) for the monoculture system and positive (r= 0.71) for the biculture system. Microaggregates coalesced even when such increase in size did not trigger a significant increase in the mean weight diameter. Secondly, microaggregates also seemed to serve as building blocks for macroaggregates.
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Papers by hupenyu mupambwa
There is substantial evidence that cover crops increase soil fertility and plant nutrition but the few studies concerning soil physical properties are conflicting. This study determined the effects of monocultures of vetch (Vicia dasycarpa L.), lupin (Lupinus angustifolius L.), oats (Avena sativa L.) and bicultures of oats and vetch and a weedy fallow on the strength and water conservation properties of a hardsetting Oakleaf soil. Oats monoculture lowered the soil strength by 48.5%, whilst vetch and lupin increased soil strength by 43% and 31%, respectively, relative to the control. Bicultures decreased soil strength as the proportion of oats increased. Oats monoculture increased cumulative water infiltration relative to the control. Bicultures increased the water final infiltration rate by 105–163% compared to the control. Plant available water increased by 24–28% compared to the weedy fallow under monocultures. However, no significant differences were observed on plant available water after two rotations with bicultures compared to the weedy fallow. We concluded that oats monoculture reduced the strength and improved water conservation properties of the hardsetting soil but vetch and lupin monoculture worsened the deleterious effects of the hardsetting phenomenon.
Mono- and biculture cropping systems are thought to affect aggregate stability by influencing soil polysaccharides but the exact relationship is uncertain. The objective of this study was to determine the effects of cover cropping systems on polysaccharides and aggregate stability in an Oakleaf soil. Two experiments involving a cereal, two legumes and a weedy control, either in mono- or biculture, were done. The crops were oat (Avena sativa L.), vetch (Vicia dasycarpa L.) and lupin (Lupinus angustifolius L.). All cover crops in both cropping systems increased soil polysaccharides. Cover crops in both systems improved aggregation either by increasing macroaggregates and/or lowering the percentage of the 0.25–0.106 mm aggregate fraction size. The mean weight diameter increased under the mono- but not biculture system. The hot-water extractable polysaccharides fraction was actively involved in aggregation in the Oakleaf soil. The correlation between hot-water extractable polysaccharides and the mean weight diameter was negative (r= −0.55) for the monoculture system and positive (r= 0.71) for the biculture system. Microaggregates coalesced even when such increase in size did not trigger a significant increase in the mean weight diameter. Secondly, microaggregates also seemed to serve as building blocks for macroaggregates.
There is substantial evidence that cover crops increase soil fertility and plant nutrition but the few studies concerning soil physical properties are conflicting. This study determined the effects of monocultures of vetch (Vicia dasycarpa L.), lupin (Lupinus angustifolius L.), oats (Avena sativa L.) and bicultures of oats and vetch and a weedy fallow on the strength and water conservation properties of a hardsetting Oakleaf soil. Oats monoculture lowered the soil strength by 48.5%, whilst vetch and lupin increased soil strength by 43% and 31%, respectively, relative to the control. Bicultures decreased soil strength as the proportion of oats increased. Oats monoculture increased cumulative water infiltration relative to the control. Bicultures increased the water final infiltration rate by 105–163% compared to the control. Plant available water increased by 24–28% compared to the weedy fallow under monocultures. However, no significant differences were observed on plant available water after two rotations with bicultures compared to the weedy fallow. We concluded that oats monoculture reduced the strength and improved water conservation properties of the hardsetting soil but vetch and lupin monoculture worsened the deleterious effects of the hardsetting phenomenon.
Mono- and biculture cropping systems are thought to affect aggregate stability by influencing soil polysaccharides but the exact relationship is uncertain. The objective of this study was to determine the effects of cover cropping systems on polysaccharides and aggregate stability in an Oakleaf soil. Two experiments involving a cereal, two legumes and a weedy control, either in mono- or biculture, were done. The crops were oat (Avena sativa L.), vetch (Vicia dasycarpa L.) and lupin (Lupinus angustifolius L.). All cover crops in both cropping systems increased soil polysaccharides. Cover crops in both systems improved aggregation either by increasing macroaggregates and/or lowering the percentage of the 0.25–0.106 mm aggregate fraction size. The mean weight diameter increased under the mono- but not biculture system. The hot-water extractable polysaccharides fraction was actively involved in aggregation in the Oakleaf soil. The correlation between hot-water extractable polysaccharides and the mean weight diameter was negative (r= −0.55) for the monoculture system and positive (r= 0.71) for the biculture system. Microaggregates coalesced even when such increase in size did not trigger a significant increase in the mean weight diameter. Secondly, microaggregates also seemed to serve as building blocks for macroaggregates.