江苏沿海地区减磷对机插常规粳稻产量形成及品质的影响

摘要

江苏沿海地区农田由于长期重视磷肥施用，土壤速效磷含量已经达到较高的水平，但目前仍然维持较高的施磷量，不仅会使施磷效果下降，还会对周围水体环境产生不利的影响.为了探讨该地区水稻减量施磷的可能性，以该地区大面积种植的迟熟中粳品种淮稻5号为材料，选择位于该地区的上海农场中等肥力的田块为试验地(土壤速效磷含量29．93 mg/kg)，研究了在正常施氮量下不施磷肥、减量施磷(常规施磷量的50％)、常量施磷(施含14％P2 O 5的过磷酸钙450 kg/hm2)、增量施磷(常规施磷量的150％)、常规氮磷钾配施和不施肥(空白)6个处理对机插秧水稻关键生育期叶片 SPAD 值、干物质积累量、产量构成和籽粒品质的影响.结果表明，不同施磷量处理拔节期、抽穗期、灌浆中期、灌浆后期 SPAD 值无显著差异，拔节期、抽穗期、成熟期干物质积累量及拔节-抽穗期、抽穗期-成熟期干物质净积累量和群体净增长率也无显著差异.不施磷、增量施磷处理千粒重显著低于减量和常量施磷处理，其他产量构成因子和经济系数在不同施磷处理间则无显著差异，减磷处理因有效穗数、每穗粒数及千粒重最高而获得9801 kg/hm2的最高产量，比常量施磷增加7．69％.从稻米品质方面看，除垩白米率减磷处理显著高于 CK 处理外，其余各指标均无显著差异.减磷处理较其他施磷处理，增加了峰值黏度和崩解值，降低了消减值，提高了稻米的食味品质.%Soil available phosphorus content of farmland has reached a high level in Jiangsu coastal area due to long-term application of large amounts of phosphate fertilizer.But current higher rates of phosphate fertilizer decreases the phos-phorus effect,even having an adverse effect on the surrounding water environment.A field experiment was conducted to investigate the effect of reduced phosphorus fertilizer application on the yield formation and quality in rice.Six treat-ments were designed as CK(no fertilization),conventional NPK fertilizer application,no phosphorus fertilization,re-duced P rate(50% of conventional phosphorus fertilization rate),conventional phosphorus fertilization,increased P rate (1 50% of conventional phosphorus fertilization).The results showed that there were no significant difference in SPAD of rice leaves among all the treatments except CK at jointing,heading,middle and late filling stages.The dry matter accumulation at jointing,heading stage,maturity stage and net dry matter accumulation as well as net popula-tion growth rate during jointing-heading,heading-maturing had also no significant difference among all the treatments except CK.The 1000-grain weight under no or reduced phosphorus treatments was significantly lower than that of con-ventional phosphorus treatments,while the rest of yield components as well as economic coefficient had no significant difference among the treatments.Due to higher effective panicle number,grain number per panicle and 1000-grain weight,the rice grain yield under reduced phosphorus treatment reached 9 801 kg/hm2 ,7.69% higher than that under the conventional phosphorus treatment.There were no significant differences in the indexes of rice quality except that the chalky grain rate under the reduced phosphorus treatment was significantly higher than CK.Due to higher peak vis-cosity and breakdown and lower setback value,the eating quality of rice under the reduced phosphorus treatment was improved.