Nutrient mining in maize-based systems of rural Zimbabwe
Mapfumo, P.
Nutrient mining in maize-based systems of rural Zimbabwe - Addis Ababa (Ethiopia) CIMMYT|EARO : 1999 - p. 274-277 - Printed
A survey was conducted to determine the nutrient status of soils from farmer's fields which had been dominated by maize cropping in previous seasons. Wherever possible, comparisons were made to soils from natural miombo woodlands which are the predominant vegetation on these granitic soils. Ten farm sites were monitored for nutrient flows and maize N, P and K uptake. Potential N mineralization averaged 10.6 mg/kg of soil in arable soils compared to 54 mg/kg in the natural ecosystem Out of the soils surveyed 77% were deficient in N and 85% deficient in P, while K was adequate in 45% of the soils. Potential N and P losses through removal of stover from fields were found to be 44% and 42% of the total uptake, respectively. Excessive nutrient depletion from these soils has possibly been precipitated by a complex management system, characterised by continuous cropping with sub-optimal nutrient inputs and driven by strong crop-livestock interactions. In this paper, the rationalization of crop residue utilization as both soil organic inputs and livestock feed is considered critical in the building and maintenance of soil nutrient stocks by smallholder farmers.
English
92-9146-065-6
Cropping systems
Ecosystems
Maize
Mineralization
Nutrients
Small farms
Soil management
Soil organic matter
Zimbabwe
Zea mays
CIMMYT
633.15 / EAS No. 6
Nutrient mining in maize-based systems of rural Zimbabwe - Addis Ababa (Ethiopia) CIMMYT|EARO : 1999 - p. 274-277 - Printed
A survey was conducted to determine the nutrient status of soils from farmer's fields which had been dominated by maize cropping in previous seasons. Wherever possible, comparisons were made to soils from natural miombo woodlands which are the predominant vegetation on these granitic soils. Ten farm sites were monitored for nutrient flows and maize N, P and K uptake. Potential N mineralization averaged 10.6 mg/kg of soil in arable soils compared to 54 mg/kg in the natural ecosystem Out of the soils surveyed 77% were deficient in N and 85% deficient in P, while K was adequate in 45% of the soils. Potential N and P losses through removal of stover from fields were found to be 44% and 42% of the total uptake, respectively. Excessive nutrient depletion from these soils has possibly been precipitated by a complex management system, characterised by continuous cropping with sub-optimal nutrient inputs and driven by strong crop-livestock interactions. In this paper, the rationalization of crop residue utilization as both soil organic inputs and livestock feed is considered critical in the building and maintenance of soil nutrient stocks by smallholder farmers.
English
92-9146-065-6
Cropping systems
Ecosystems
Maize
Mineralization
Nutrients
Small farms
Soil management
Soil organic matter
Zimbabwe
Zea mays
CIMMYT
633.15 / EAS No. 6