在玉米-大豆轮作系统中种植冬季覆盖作物黑麦有助于减小地下排水量和硝态氮(NO_3^--N)的流失量。该研究利用美国爱荷华州的试验数据校正和验证了DRAINMOD-N II模型在美国寒冷地区的适用性,并模拟长期(20 a)种植冬季覆盖作物黑麦对地下...在玉米-大豆轮作系统中种植冬季覆盖作物黑麦有助于减小地下排水量和硝态氮(NO_3^--N)的流失量。该研究利用美国爱荷华州的试验数据校正和验证了DRAINMOD-N II模型在美国寒冷地区的适用性,并模拟长期(20 a)种植冬季覆盖作物黑麦对地下排水量和氮素运移的影响。结果表明,模型模拟地下排水量和NO_3^--N流失量时,Nash-Sutcliffe模型效率系数(Nash-Sutcliffe efficiency,NSE)>0.65、百分比偏差(percent bias,PBIAS)在±25%之间、均方根误差与标准差比值(ratio of root mean square error to standard deviation,RSR)≤0.7均在误差范围内;模拟地下排水中NO_3^--N浓度时,NSE>0.50、PBIAS在±15%之间、RSR≤0.5均在误差范围内,说明模型模拟的效果好。长期种植冬季覆盖作物黑麦可降低排水量8.1%(2.5 cm),减小NO_3^--N流失量16.6%(6 kg/hm^2),NO_3^--N流量加权平均浓度下降了8.6%(1 mg/L,以N计),增加蒸散值5.9%,模型模拟值与实测值拟合效果好,表明模型具有良好的水文和氮素运移模拟功能,可以模拟不同农田管理措施对地下水和氮素运移的长期影响,为优化农田管理措施提供参考。展开更多
Little is known on the effects of biochar on N uptake and amino acid variability in crops such as winter rye and narrow-leafed lupine despite the fact that amino acids are important indicators,for food quality and pla...Little is known on the effects of biochar on N uptake and amino acid variability in crops such as winter rye and narrow-leafed lupine despite the fact that amino acids are important indicators,for food quality and plant stress.N uptake of both crops showed contrasting results when treated with different biochar fertilizers.Total amino acid contents referred to total nitro-gen generally tend to decrease in rye grains in the presence of biochar;whereas lupine seeds were more or less unaffected by biochar combined with mineral fertilizer or compost.In lupine seeds,total amino acid contents significantly increased when biochar was mixed with digestate but decreased when mixed with fermented digestate.Lysine,one of the most limiting amino acids in cereals,reached the recommended value of 4 g kg^(−1) in rye grain for most biochar fertilizers.In lupine seeds,lysine decreased when biochar had been applied but were still in the recommended range when used as animal feed.Proline,an indicator for plant stress,significantly decreased(−49%)in rye when 2 Mg biochar ha^(−1) was added in combination with mineral fertilizer.In contrast,proline increased when biochar was added to organic(digestate and compost)fertilizers(up to 43%).Further biochar research should focus much more on food quality,which is a key challenge for global food production.展开更多
基金国家高技术研究发展计划(863计划)(2013AA102904)高等学校学科创新引智计划(111计划)资助项目(B12007)Iowa Department of Agriculture and Land Stewardship
文摘在玉米-大豆轮作系统中种植冬季覆盖作物黑麦有助于减小地下排水量和硝态氮(NO_3^--N)的流失量。该研究利用美国爱荷华州的试验数据校正和验证了DRAINMOD-N II模型在美国寒冷地区的适用性,并模拟长期(20 a)种植冬季覆盖作物黑麦对地下排水量和氮素运移的影响。结果表明,模型模拟地下排水量和NO_3^--N流失量时,Nash-Sutcliffe模型效率系数(Nash-Sutcliffe efficiency,NSE)>0.65、百分比偏差(percent bias,PBIAS)在±25%之间、均方根误差与标准差比值(ratio of root mean square error to standard deviation,RSR)≤0.7均在误差范围内;模拟地下排水中NO_3^--N浓度时,NSE>0.50、PBIAS在±15%之间、RSR≤0.5均在误差范围内,说明模型模拟的效果好。长期种植冬季覆盖作物黑麦可降低排水量8.1%(2.5 cm),减小NO_3^--N流失量16.6%(6 kg/hm^2),NO_3^--N流量加权平均浓度下降了8.6%(1 mg/L,以N计),增加蒸散值5.9%,模型模拟值与实测值拟合效果好,表明模型具有良好的水文和氮素运移模拟功能,可以模拟不同农田管理措施对地下水和氮素运移的长期影响,为优化农田管理措施提供参考。
基金We acknowledge the Federal Ministry of Education and Research(BMBF)for financial support within the ClimaCarbo project(No.01LY1110B)。
文摘Little is known on the effects of biochar on N uptake and amino acid variability in crops such as winter rye and narrow-leafed lupine despite the fact that amino acids are important indicators,for food quality and plant stress.N uptake of both crops showed contrasting results when treated with different biochar fertilizers.Total amino acid contents referred to total nitro-gen generally tend to decrease in rye grains in the presence of biochar;whereas lupine seeds were more or less unaffected by biochar combined with mineral fertilizer or compost.In lupine seeds,total amino acid contents significantly increased when biochar was mixed with digestate but decreased when mixed with fermented digestate.Lysine,one of the most limiting amino acids in cereals,reached the recommended value of 4 g kg^(−1) in rye grain for most biochar fertilizers.In lupine seeds,lysine decreased when biochar had been applied but were still in the recommended range when used as animal feed.Proline,an indicator for plant stress,significantly decreased(−49%)in rye when 2 Mg biochar ha^(−1) was added in combination with mineral fertilizer.In contrast,proline increased when biochar was added to organic(digestate and compost)fertilizers(up to 43%).Further biochar research should focus much more on food quality,which is a key challenge for global food production.
