江西省水稻氮肥推荐施肥体系研究

研究了江西省不同稻田土壤氮素状况和水稻产量目标下的氮肥用量及其调整系数,以建立适合江西省的水稻氮肥推荐施肥体系,为省级区域水稻氮素推荐施肥提供科学依据。以在江西88个县(市、区)布置的1 207个"3414"水稻施肥田间试验及其采集土壤、植株进行室内分析得到的数据为基础,分别进行相关和回归等定量分析。研究结果表明:氮肥增产效果明显,平均每千克氮可增产稻谷11.2 kg,但达到最佳施用量后,随着施氮量的增加水稻增产效应降低,最佳施肥处理为N_2P_2K_2。碱解氮和全氮与相对产量的相关系数分别为0.591 5和0.233 2,尽管都达到极显著水平,但碱解氮相关系数远高于全氮与相对产量的相关系数,说明碱解氮更能反映稻田土壤的供氮能力。应用回归方程得出不同碱解氮含量时的水稻施氮量分别是:碱解氮含量分别为60、120、170、250 mg/kg时的水稻最佳施氮量分别为175、160、150、120 kg/hm~2。根据不同碱解氮含量下的水稻施氮量,再结合目标产量法,得出了不同土壤碱解氮含量时的氮肥施用调整系数分别为0.8、0.9、1.0、1.1和1.2及推荐施氮量计算公式,计算了江西省分别在7 500和9 000 kg/hm2目标产量下不同土壤碱解氮时的氮肥推荐参考值。

Study on the recommended nitrogen fertilization system of rice in Jiangxi province

This paper studied the soil N status in different paddy fields and the amount of used N fertilizer and its adjustment coefficient to reach rice yield target in Jiangxi province, in order to establish the recommended N fertilization system for rice in provincial area. Based on the data from 1 207 sites’ field “3414” experiment distributed in 88 counties for rice fertilization, and from collected soil and rice plant analyzed in laboratory, the correlation coefficients and regression equations was analyzed, respectively. The results showed that N had the significant effect for rice yield, and average per kilogram N increased the rice yield by 11. 2 kg. But after the best amount of application, with the increase of N application content, the yield of rice in-creased, and the optimum fertilization treatment was N2 P2 K2 . The correlation coefficients between soil available N and relative yield and between total N and relative yield were 0. 591 5 and 0. 233 2, respectively. Although both coefficients reached ex-tremely significant level, the coefficient of available N was higher than that of total N. This indicated that soil available N was more capable of reflecting the ability of paddy soil N supply. The optimum N content for rice in different available N content was: the best N application was 175 kg/hm2 , 160 kg/hm2 , 150 kg/hm2 and 120 kg/hm2 when soil available N content was 60 mg/kg, 120 mg/kg,170 mg/kg and 250 mg/kg, respectively. According to the nitrogen application value under different soil available N content, and combination with the target yield method, the adjustment coefficient of nitrogen fertilizer application was 0. 8, 0. 9, 1. 0, 1. 1 and 1. 2 in different soil available N content, respectively. The recommended values of N applica-tion in different soil available N contents at 7 500 kg/hm2 and 9 000 kg/hm2 of target yield in Jiangxi province were calculated.