基于耕作指数评价东北风沙土肥沃耕层构建周期效果

Evaluating Fertile Topsoil Construction in Aeolian-sandy Soil in Northeast China Based on Tillage Index

评价不同肥沃耕层构建模式周期对东北风沙土耕层质量的影响,为该地区合理肥沃耕层构建模式选择提供科学依据,采用系统聚类方法建立了东北风沙土肥沃耕层评价指标的最小数据集(MDS),结合最小数据集的耕作指数(TI-MDS)定量评价了传统耕作、免耕、打破犁底层、传统耕作+有机肥和翻耕+秸秆还田5种不同肥沃耕层构建方式下的东北风沙土耕层构建一个循环周期后的质量,并采用Nash有效系数(Ef)和相对偏差系数(Er)加以验证。结果表明:全量数据集耕作指数(TI-TDS)均值为0.47,最小数据集耕作指数(TI-MDS)均值为0.48,TI-TDS与TI-MDS相关系数R为0.958**,二者呈显著正相关。TI-MDS与玉米产量呈显著正相关(R=0.895**),Nash有效系数(Ef)为0.909,偏差系数(Er)为0.017,可见TI-MDS合理性较高,可用于定量评价风沙土耕层土壤质量。由耕作评价指数可知,与传统耕作对照相比,传统耕作+有机肥模式的土壤质量提高了一个等级,达到高肥力水平;而与免耕、打破犁底层和翻耕+秸秆还田3种模式的耕层土壤质量差异不显著,保持在中肥力水平。本研究结果表明,在东北风沙土农业生产过程中,采取传统耕作配施有机肥的肥沃耕层构建模式值得推广应用。

Evaluating the impact of fertile topsoil construction model on the quality of Aeolian-sandy soil in northeast China can provide a scientific basis for the selection of reasonable construction model in this area.Systematic clustering method was used to establish the minimum data set(MDS)of evaluating index of the fertile topsoil.Combined with the tillage index of the minimum data set(TI-MDS),the construction quality of the topsoil in Aeolian-sandy soil in northeast China was quantitatively evaluated across five different construction models,including conventional tillage,no tillage,breaking the plough pan,conventional tillage plus organic fertilizer and ploughing plus straw returning.Nash effective coefficient(Ef)and relative deviation coefficient(Er)were used to verify the quality.The results showed that the mean value of the full data set(TI-TDS)and TI-MDS was 0.47 and 0.48,respectively,positive correlations were shown between TI-TDS and TI-MDS(R=0.958**),and between TI-MDS and corn yield(R=0.895**).The Efand Erwere 0.909 and 0.017,respectively,which indicated that the TI-MDS was reasonable and suitable to evaluate the topsoil quality of Aeolian-sandy soil.According to the tillage index,compared to conventional tillage,the construction model of conventional tillage plus organic fertilizer could improve soil quality by a level from medium to high.However,the topsoil quality did not show significant difference among no tillage,breaking the plough pan and ploughing plus straw returning.In summary,in agricultural production process in Aeolian-sandy soil in northeast China,the construction model of conventional tillage combined with organic fertilizer is worthy of recommending.