湖南双季稻种植区不同生产力水稻土质量综合评价

【目的】利用非线性评价模型量化不同生产力水稻土的质量变化,为双季稻种植区水稻土的可持续利用提供科学依据。【方法】以湖南省双季稻主产区为试验样区,采用综合评价方法,将土壤质量划分为抗物理退化、养分供应与贮藏、抗生物化学退化和保持作物生产力这4项土壤功能。运用专家小组打分和因子分析相结合的方法,确定各项功能和指标的权重,用非线性评分模型对不同生产力水稻土测定的各项指标进行无量纲(0和1之间)评分。【结果】结果表明,8个试验区高产水稻土具有良好的物理、化学和生物化学质量;中产水稻土的物理质量比较好,但生物化学质量较差;低产水稻土的物理、化学和生物化学质量均较差,主要体现在有机质含量低,养分供应、贮藏能力差。【结论】高产水稻土的总体土壤质量高,对双季稻生长不构成障碍;影响中产水稻土质量的主要因子是养分供应不平衡,采用良好的管理措施可以使其土壤质量在短期内得以提高;低产水稻土的总体质量差,在这类水稻土上需要增加有机肥和无机养分的投入,改善其总体土壤质量。

Comprehensive Evaluation of Soil Quality in Different Productive Paddy Soils in Typical Double-Rice Cropping Regions of Hunan Province

【Objective】 A non-linear assessment model was used to quantify the changes of paddy soils with different productivities and provide a scientific basis for sustainable use of paddy soil in double-rice growing area. 【Method】 This study was conducted in important double-rice producing areas. A comprehensive method for evaluating soil quality was adopted. Soil quality was evaluated according to four major soil functions, i. e., resistance to physical degradation, nutrient supply and storage, resistance to biochemical degradation and conservation of crop productivity. Every soil function and individual soil indicator was weighted on the basis of the expert opinion panel and statistical tools such as factor analysis,then soil property values measured under different productive paddy soil were transformed into unitless scores (between 0 and 1) using non-linear score equation. The non-linear assessment model based on soil function could comprehensively evaluate the soil quality, which can be directly reflected by this method. 【Result】 Results showed that high yield paddy soils in eight experimental areas have physical, chemical and biochemical qualities. The middle yield paddy soil has good physical and biochemical qualities, but poor chemical qualities. The physical, chemical and biochemical qualities in low yield paddy soils were all poor, which mainly reflected low organic matter, nutrient supply and storage ability. 【Conclusion】 Overall soil quality of high yield paddy soil was good, which did not create obstacles to double rice growth. The main factor affecting middle yield paddy soil was unbalance of soil nutrient supply in the soil. The overall soil quality of low yield paddy soil was poor, input of increasing organic matter and inorganic nutrient is required for improvement of the overall soil quality in this type of paddy soil.