Effects Of Long-term Located Fertilization On Forms Distribution Of Soil Calcium In Protected Field

Greenhouse developed rapidly in recent years, but the study of protected soil almost on large elements such as N P K. The research of the effectiveness of calcium is rarely. So, the objective of this study is to investigate the influence of different fertilizer treatment on calcium forms distribution base on long-term located fertilization protected soil, and to find out affecting factors and mechanism for the effectiveness of calcium. The results are summarized as follows:1. Organic fertilizer could increase the supply of calcium level of soil. Because of many kinds of organic fertilizer contain Ca, and it can reduce the leaching of Ca from mitigating pH change, reducing leaching of Ca.2. The increasing of nitrogen fertilizer causes the rising of water soluble Ca and reducing the content of others. Because of nitrogen fertilizer causes soil acidification, affects calcium content and formation distribution in soil and promoting the leaching of Ca. Nitrogen fertilizer is the main factors of affecting Ca distribution.3. The influence of potassium to Ca is not obvious. Potassium is not contains Ca. It does not affect pH value significant. In soil solution, exchange capacity of K+ less than Ca+. Phosphorus can increase the content of Ca. But it has not good regularity of the distribution of forms of Ca with phosphorus.4. The content of total calcium, water soluble calcium and un-acid soluble calcium on 0-20cm soil are higher than 20-40em soil. With the increased amount of nitrogen fertilizer, the difference of distribution of soil total calcium, water soluble calcium content in two soil increased gradually. Potash has no significant influence. P increased 0～20cm and 20-40cm Ca content of soil layers, but did not change the different forms Ca distribution of soil in two soil layers. The effectiveness of calcium in the soil profile downward happening on the move. The effectiveness of surface soil is low.5. Total calcium content and un-acid calcium content have significant positive correlations with pH and SOM. Water soluble calcium content has significant negative correlation with pH and SOM. So the reducing of pH promotes the leaching of Ca and the increasing of SOM promotes the accumulation of Ca.6. The small granular of the soil are mainly influencing the distribution of Ca content. In surface soil, the otherness of different configuration calcium content in different sized soils on Nitrogen with organic fertilizer treatment is smaller than Nitrogen treatment. Organic fertilizer promotes the formation of the body, causing the Ca content is higher in the larger granular soil. As center, Ca can promote the soil grain and was reunited in bigger soil. The otherness in 20-40cm soil is not obvious, because the O.M. content is lower.7. Potassium fertilizer can promote the ability of accumulating Ca of bigger sized soils. Nitrogen with potassium fertilizer treatment improves the content of water soluble calcium in all different sized soils. In addition to this, apply potassium negative affect content Ca in different sized soils. Potassium does not affect pH value significantly, so it does not affect the distribution of different forms Ca in soil.8. The ability of accumulate Ca of 0.1～0.2mm is enhanced by only fertilizing phosphate or with others. Supply phosphate can increase the different morphology calcium content in all sized soils except un-acid soluble calcium. Water soluble calcium performance remarkable in<0.1mm sized soil, except this the trend is significant in bigger sized soils in 0-20cm soil, and in 20-40cm smaller sized soils have notable performance.9.<0.1mm has biggest contributing rate to Ca among the different sized soils. In 0-20cm soil, the treatments of organic fertilizer increase the contributing rate of larger sized soil and reduce the otherness of contributing rate between different sized soils. Organic fertilizer promote Ca to combined to larger sizes soil, while improving the percentage of bigger sizes soil, to increase the contribution of calcium content in large granular. This otherness in 20-40cm soil is not obvious.