不同农业耕作模式下崇明盐碱土壤低碳化改良效应的模型评价

Assessment of Different Agricultural Pattern for Amelioration of Salty Soil by Low Carbon Model in Chongming,China

对不同农业耕作模式的崇明滨海盐碱土进行了为期15个月的跟踪采样,通过分析土壤的10余种物理、化学和生物指标,在原始数据呈现季节性波动的情况下,借助主成分分析的数学方法将对土壤的多指标评价转化为单一综合指标的评价。在通过数学模型强化土壤改良效果的显著性和规律性的同时,将土壤呼吸和生物量作为评价指标之一,得出了不同于传统土壤评价系统的结论。模型评价结果显示,a、b、c3区传统评价体系的综合主成分得分为0.4131、-2.6217和2.20858,3区加和土壤呼吸和生物量后的综合主成分得分为-1.6989、-2.28724和3.98612,3区的耕作模式的差异表明不同样地的综合主成分得分和农业利用模式的多样性相关,多样化的耕作模式虽然加强了土壤的呼吸,但同时导致了该样区生物量的显著提高。因此加和了土壤呼吸和生物量的综合主成分得分仍然高于未加和这两项指标的得分。就实验样地而言,多样化的土壤利用模式可能得到比较理想的改良效果。

In order to assess amelioration effect of different agricultural pattern on salty soil in Chongming Island,several kinds of physical,chemical and biological indexes of the soil samples area A,B,C with different agricultural patterns of cauliflower-orange,forage grass,cornbarley-watermelon-cauliflower respectively,had been monitored for 15 months.Although the original data fluctuated seasonally,the principal components analysis method transferred the multiple indicators into single aggregative indicators to intensify the regularity and significance of the results and efficiently assess the soil fertility.Furthermore,the model involved the soil respiration and biomass as indicators for the assessment of carbon sink capacity of different patterns.The traditional aggregative principal components remarks in sample areas A,B and C,were 0.413 1,-2.621 7 and 2.208 58 respectively.This implied that amelioration effect were relevant with the diversity of agricultural pattern.The corn-barley-watermelon-cauliflower pattern was the most effective way to ameliorate the soil among three patterns.After combining the soil respiration and biomass indicators,the remarks were-1.698 9,-2.287 24 and 3.986 12 respectively.The corn-barley-watermelon-cauliflower pattern intensified the soil respiration while the biomass rose at the same time.Consequently,its remark was still higher than the one without the two indicators.That means this pattern may still get a better result in the views of both fertility and carbon sink.