淹水条件硝态氮和铵态氮配施对水稻生长与土壤养分的影响

Effects of Combined Application of Nitrate and Ammonium on Rice Growth and Soil Nutrients Under Flooding Conditions

为系统研究硝态氮、铵态氮及二者不同配施比例对土壤养分供应与水稻生长情况的影响,通过田间小区试验,在相同施氮量条件下,研究了单施硝态氮(N),单施铵态氮(A),硝态氮、铵态氮按1︰3(N1A3)、2︰2(N2A2)、3︰1(N3A1)比例配施对水稻产量、田间养分和氮素利用率的影响,并与农民习惯性施肥方式(U)作比较。研究结果表明:整个生育期内铵态氮对水稻的生长都起着主要作用,铵态氮通过提高水稻氮素利用率和促进水稻有效分蘖的方式提高了水稻产量。随着铵态氮的配施比例由25%提高到75%,水稻的产量提高了35.18%、氮素利用率提高了46.67%,每公顷产生的经济收益增加了6820.15元。A处理土壤中硝态氮、铵态氮和碱解氮的含量较N处理显著增加36.41%、30.30%和8.42%,水稻产量提高了60.11%,氮素利用率提高了171.31%,有效穗数增加了52.31%,相较农民习惯性施肥,单施铵态氮处理每公顷还能增收522.91元。在0~180 kg/hm2的施氮量范围内,水稻产量(y)与铵态氮施用量(x2)呈显著正相关,二者之间关系为y=18.044x2+4943.4(R2=0.9753)。

A field plot experiment at the same nitrogen application rate was carried out to study the effects of different nitrogen forms and ratio(treatment N:nitrate nitrogen only,treatment A:ammonium nitrogen only,nitrate and ammonium nitrogen mixed at the ratio of 1:3,2:2,3:1,treatment N1A3,N2A2 and N3A1,respectively)on rice yield,yield factors,soil nutrients and nitrogen use efficiency,with the conventional fertilization(treatment U,farmer habitual fertilization)as CK.Results showed that ammonium nitrogen played a major role in rice growth during the whole growth period of rice,ammonium nitrogen increased nitrogen use efficiency and promoted the effective rice tillering.With the proportion of ammonium nitrogen applied from 25%to 75%,rice yield increased by 35.18%,nitrogen utilization rate increased by 46.67%,and economic benefit per hectare increased by 6820.15 yuan.After harvesting,compared with treatment N,treatment A increased soil nitrate nitrogen by 36.41%,ammonium nitrogen by 30.30%,hydrolyzable nitrogen by 8.42%,rice yield by 60.11%,nitrogen utilization rate by 171.31%and effective panicles by 52.31%,respectively.Compared with treatment U,treatment A increased economic benefit by 522.91 yuan per hectare.There was a significant positive correlation(y=18.044 x2+4943.4,R2=0.9753)between rice yield(y)and ammonium nitrogen application(x2)within the application range of 0-180 kg/hm2.