海南水稻土有机质的时空变异

根据2004年采集的300个海南不同地区水稻土耕作层样品分析数据和第二次土壤普查的706个剖面点资料，对全省水稻土有机质时空变异特征进行了研究和分析。结果表明，海南水稻土有机质近20多年来下降十分明显，根据第二次土壤普查标准，属于“丰”水平的样点数从31.9%下降到22.4%，“中”水平的样点数变化不大，基本保持在31%左右，而“缺”水平样点数明显增加，从37.3%升高到46.6%，说明改变当前海南农民重化肥、轻有机肥偏向，大力提倡秸杆还田，增施有机肥，补充土壤有机质是维持海南水稻田地力的当务之急。

Spatial-temporal Variance of Paddy Soil Organic Matterin Hainan Province

The spatial-temporal variance of soil organic matter was researched in this paper in terms of 300 paddy soil samples in 2004 and 706 paddy soil samples of The Second Soil Survey of China in Hainan Province.The results indicated that the soil organic matter in paddy soil of Hainan Province was decreased during the past 20 years.According to the criterions which was established in The Second Soil Survey of China.The number of regions whose soil organic matter was in the abundance level was decreased from 31.9% to 22.4%.The number of regions whose soil organic matter was in the middle level had changed little,maintaining around 31%.The number of regions whose soil organic matter was in the lack level was increased from 37.3% to 46.6%.The results showed that it was very essential to the preservation of soil fertility with increasing organic fertilizer and straw returned to field.