[Effect of plastic-film mulch on water and nitrogen use by spring maize and on fate of applied nitrogen in the southern Loess Plateau].
The relationships between nitrogen and yield and between water and yield, and the fate of nitrogen under plastic film mulching for spring maize were studied with field plots and microplots in the southern Loess Plateau. The results showed that plastic-film mulching (N120C) could increase maize yield by 46.7%, comparing with no-mulching(N120UC) in same rate of fertilizer. The maize yield potentiality of mulching might be played fully, comparing with CK (no nitrogen), treatments N120 (urea nitrogen 120 kg.hm-2), N180 (urea nitrogen 180 kg.hm-2) and N120 M (urea nitrogen 120 kg.hm-2 + organic manure nitrogen 60 kg.hm-2) could raise grain yield by 41.8%, 43.9% and 34.7%, respectively. Mulching planting raised water use efficiency (WUE) by 57.9%, and raised rainfall use efficiency (RUE) by 54.5%. N120, N180 and N120M improved WUE by 38.4%, 47.4% and 32.4%, respectively, and improved RUE by 42.3%, 43.9% and 34.7%, respectively. Because the organic manure applied was not fully rotted cattle dung, which supplied available nitrogen slowly than urea, it raised yield and WUE to a low extent. Meanwhile, the experiment showed that 73.0%-83.7% of water used by maize from rainfall, which indicated that the key water to determine maize yield was rainfall in spring maize growth period. Mulching planting for maize had little impact on the fate of nitrogen fertilizer. The total recovery of nitrogen had little difference, NUE decreased 7.3%, and residual N in soil raised 6.4%, comparing with N120UC. A great part of the residual N was in 0-20 cm of soil, and no risk occurred for nitrogen leaching and accumulation to deeper soil layers in the first growth season.
Dang
Tinghui
T
Institute of Soil and Water Conservation, CAS and MWR, Northwest Sci-Tech. University of Agriculture and Forestry, Yangling 712100, China. dangth@sina.com
Hao
Mingde
M
Guo
Shengli
S
Cai
Guixin
G
D018556:Crops, Agricultural / Q000254:growth & development*; D005308:Fertilizers; D009584:Nitrogen / Q000378:metabolism*; D014867:Water / Q000378:metabolism*; D003313:Zea mays / Q000254:growth & development* / Q000378:metabolism
D005308:Fertilizers; D014867:Water; D009584:Nitrogen