Effects of Nitrogen Application on Yield,Quality,and Nutrient Absorption and Utilization Characteristics of Summer Maize under Straw Incorporation
Field experiments were conducted separately in Wenxian County in 2019,Yuanyang County and He-bi City in 2020,Henan Province,China.To study the effects of nitrogen application rates on grain yield,quality,physicochemical and N utilization characteristics of summer maize under straw returning mode,and provide a scien-tific basis for the optimal N application in this region.The results showed that the yield of summer maize increased with increasing N application rates in"linear+platforms trends".The crude protein,crude fat and crude starch in summer maize stopped increasing when the N application rate reached 240 and 280 kg/ha.Compared with the N0 treatment,N application increased crude protein,crude fat and crude starch by 30.6％,30.4％,and 1.5％on average in 2 years,respectively.The plant physiological indicators,such as the leaf SPAD value,FPAR and leaf nitrogen content increased with increasing N application rates.The N harvest index decreased gradually with the increase of N application rates,and the apparent utilization and agronomic efficiency increased first and then decreased with the increase of N application rate.Therefore,under the straw returning mode,reasonable nitrogen application can significantly increase summer maize grain yield,improve quality,enhance physiological activity at each growth stage,and improve fertilizer utilization efficiency.The recommended N application rates in the experimental area was 230-260 kg/ha.
Summer maizeStraw incorporationNitrogen rateYieldQualityNitrogen use efficiency
NETL
NSTL
万方数据
