Nitrogen balance under non-tillage maize (Zea mays L.) cultivation after hairy vetch (Vicia villosa Roth.) cropping at sloping fields

Nagumo, Fujio
Nakamura, Ken
Soil Science and Plant Nutrition
Publication Year: 
Leguminous plants are often cropped before main cropping in conservation agriculture based cropping systems. However, their quick decomposition and subsequent nitrogen (N) release may cause N leaching. In order to understand the effects of non-tillage cropping combined with hairy vetch (Vicia villosa Roth.) fallow as a cover crop on N balance considering water balance at sloping fields, an experiment was conducted on a sloping field at the Japan International Research Center for Agricultural Sciences (JIRCAS), Tropical Agriculture Research Front (TARF), Ishigaki Island, Okinawa Prefecture, Japan. Two fallow systems (natural and hairy vetch; HV) were combined with 2 soil tillage treatments (non-tillage and conventional tillage). Maize (Zea mays L.) was planted after the soil tillage treatment. Non-tillage after HV with half of the recommended fertilizer (vZ-1/2F) obtained similar grain yield (oven-dry basis; 5747 kg ha?1) to tillage after HV with half of the recommended fertilizer (vT-1/2F), non-tillage after natural fallow with recommended fertilizer (fZ-1F), and tillage after natural fallow with recommended fertilizer (fT-1F). It demonstrated a high effect of HV as substitute for chemical fertilizer for the succeeding crop. Leached nitrate-nitrogen (NO3-N) during the maize cropping was highest for vZ-1/2F (36.5 kg ha?1), followed by vT-1/2F (12.7 kg ha?1) and fT-1F (11.1 kg ha?1). A significant turnover of HV-N to the soil probably resulted in high N leaching for vZ-1/2F. Available N, calculated as fertilizer N + available rate x HV-N + Soil N, was almost equal to the sum of N uptake by maize and leached N. The residue mulch with non-tillage (vZ-1/2F) decreased water runoff, resulting in increased percolation. However, the NO3-N concentration in the percolated water was a much more important factor for N leaching calculation than the amount of percolation. This increased NO3-N concentration was probably due to decomposition of the HV biomass produced. However, the total N balance for maize cropping after HV fallow showed significant N surplus in the soil at the end of cropping. This must contribute to soil fertility improvement.
Name of Journal: 
Soil Science and Plant Nutrition
Resource Type: 
Document Type: 
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Grassland Society of Southern Africa

The Grassland Society of Southern Africa (GSSA) is involved and concerned with the science and practice of range and pasture management. This broad field involves primarily the use and conservation of natural resources. It encompasses applied fields such as livestock production, wildlife management, nature conservation, water catchment management and range and mine-dump rehabilitation. The disciplines include, amongst others, ecology, botany zoology, range and pasture science, animal science, soil science and genetics. This collection includes journal articles from the African Journal of Range and Forage Science as well as related articles and reports from throughout the Southern African region.