节水灌溉下不同氮肥施加对稻米品质变异性的影响

Effect of Nitrogen Fertilizers Application on Variability of Quality of Paddy with Water-saving Irrigation

为探讨黑土区不同氮肥施加对稻米品质及变异性影响,在节水灌溉条件下以0、60、85、110、135、160 kg/hm^2氮肥处理的典型黑土区水稻生长基质为例,采用水稻成熟期蛋白质含量、直链淀粉含量、垩白度3个主要品质指标田间系统采样数据为研究对象,运用地统计学原理探讨了水稻3个品质指标的变异性,并建立了半变异函数模型。结果表明:不同施氮量不仅能够促进稻米品质的改善,而且可以改变田间区域内稻米品质的变异性,除垩白度和不施氮肥处理的蛋白质含量属中等变异外,其他处理下的水稻3个品质指标均属于弱变异。3个指标中直链淀粉含量正相关范围最大,大于蛋白质含量和垩白度正相关范围,表明黑土区不同氮肥管理对直链淀粉含量变异结构影响最大。同时随着施氮量的增加,土壤中硝态氮和铵态氮呈先增加后减小的变化趋势,不同施氮量土壤硝态氮和铵态氮含量的变化与稻米品质变异强度的顺序恰好相反,由大到小为WS0、WS60、WS85、WS160、WS135、WS110,通过相关性分析得出硝态氮对稻米品质变异性起主导作用,表明不同氮肥的施加可以通过改变土壤中硝态氮和铵态氮的含量进而对稻米品质变异性有一定的影响。综合来看最佳氮肥施用量为110 kg/hm^2,水稻3个品质指标及其生长基质均具有较好的区域化特征和空间结构。同时引入地统计学理论不仅弥补了经典统计分析的不足,而且可为水肥—土壤—作物系统信息进行空间结构和定量化研究提供理论依据。

In order to discuss the effects of nitrogen fertilizers application on the variability of paddy quality in black soil region,the example of black soil of typical cold area was taken and treated with 0,60 kg/hm^2,85 kg/hm^2,110 kg/hm^2,135 kg/hm^2 and 160 kg/hm^2 of nitrogen fertilizer under water saving irrigation condition. The field system sampling data for three main paddy quality indicators of protein,amylose and chalkiness in mature paddy were studied,the variability of three paddy quality indicators was investigated by using geostatistics theory,and a semi-variogram model was established.The results showed that the different nitrogen applications can not only promote paddy quality improvement,but also reduce paddy quality difference in the field area. Except that chalkiness and protein treated with no nitrogen fertilizer was the medium variation,all the other treatments were weak variation. In these three indicators,amylose was the most largest positive space correlation range,which was greater than the positive correlation of protein and chalkiness space. It was showed that the water and nitrogen management had the greatest influence on the variability of amylose in cold region. With the increase of nitrogen application rate,the nitrate nitrogen and ammonium nitrogen in soil were increased first and then decreased. The changes of nitrate and ammonium nitrogen contents in soils with different nitrogen application rates were in the opposite order to the spatial variation of paddy,which were in adescending trend as WS0,WS60,WS85,WS160,WS135 and WS110,it was showed that the different nitrogen contents had some influence on the variability of paddy quality,the results showed that the application of different nitrogen fertilizers could change the contents of nitrate and ammonium nitrogen in soil and then had a certain impact on the rice quality variability. The optimum nitrogen fertilizer application was 110 kg/hm^2,and the three paddy quality indexes and its growth matrix had good regional characteristics and spatial structure. The introduction of geostatistics not only compensated the deficiency of classical statistical analysis,but also provided theoretical basis for spatial structure and quantitative research of water-fertilizer-soil-crop system information.