长期施肥对早稻产量和杂草群落的影响

Effects of long-term fertilization on weed community and early rice yield of reddish paddy field

利用1982年布置的双季稻红壤稻田长期施肥定位试验,于2011年研究了在无机肥(化肥NPK)与有机肥(M)氮磷钾养分等量条件下,长期施用有机肥、无机化肥和有机无机肥配施模式下早稻生长发育、早稻产量及稻田杂草群落变化。结果表明:施肥能促进早稻生长发育,显著提高早稻产量,增加施肥用量和均衡肥料及养分种类在一定程度上能促进早稻生长发育和稻谷增产;在施用有机肥的基础上,优先考虑施用氮肥,其次是磷肥,才能使红壤稻田早稻增产。施肥处理中,单施有机肥最能提高早稻杂草密度和促进早稻杂草生长,配施处理中,有机无机均衡配施最能促进早稻杂草生长,还能遏制恶性杂草繁殖;与单施有机肥或化肥相比较,有机无机肥配施能普遍降低早稻杂草群落多样性、优势度和均匀度,在施用有机肥的基础上,化肥尤其是化肥氮的施用对早稻杂草群落的多样性、优势杂草和均匀度起着决定性作用;早稻分蘖盛期杂草生物量一定程度上还能表征早稻稻谷产量。

An investigation was made at a double-rice reddish paddy field estabnsned in 1982 to study the growth and development and grain yield of early rice and species and biomass of weeds after 30-year application of organic fertilizer, chemical fertilizer, organic and inorganic fertilizer at the same application rates of nitrogen （N）, phosphorus （P）, and potassium （K） contained in chemical fertilizer and organic fertilizer. The results showed that fertilization promoted the growth and significantly increased the yield of early rice. To some extent, increasing amount of fertilizers and balancing types of fertilizers and nutrients promoted the growth and yield of early rice. On the basis of applying organic fertilizer, applying nitrogen fertilizer in priority, followed by applying phosphate fertilizer, could increase early rice yield in reddish paddy soil. Among all the fertili- zation treatments, single-organic fertilizer apphcation had the best effect in increasing the density and promoting the growth of weeds; among all combined application of organic and inorganic fer- tilizer treatments, balanced combined application had the best effect in promoting the growth of weeds, in particular, suppressing the reproduction of malignant weeds. Compared with organic fertilizer or chemical fertilizer application alone, combined application of organic and inorganic fertilizers generally reduced the diversity, dominance and evenness of weed community in early rice field. Long-term application of chemical fertilizer, especially nitrogen fertilizer played a deci- sive role in the diversity, dominance and evenness of weed community on the basis of applying organic fertilizer. The weed biomass at the active tillering stage of early rice could represent early rice grain yield to a certain extent.