Effects of Solid Organic Wastes on Soil Particulate Organic Carbon Structure Under Different Water Conditions

Abstract

In searching for the optimum method for amelioration of solid organic waste by remedying black soil and tackling rainfall changes, effects of water conditions and solid organic wastes are studied on particulate organic carbon (POC) structure by 13C‐NMR spectroscopic analysis in a 3‐year split‐plot experiment. Experimental plots are under natural rainfall, water deficit, and excess water with single chemical fertilizer, cow manure, chicken manure, crop, or plant residue treatments. The results reveal that solid organic wastes have the potential to improve POC stability. Under natural rainfall conditions, the degressive order by the POC stability is plant residue, crop residue, cow manure, and then chicken manure; under water deficit, it is plant residue, crop residue, chicken manure, and then cow manure; under excess water conditions, it is plant residue, cow manure, chicken manure, and then crop residue. The interchange between aromatic carbon and alkyl or alkoxy carbon gives a remarkable reflection of the effect of water on POC structure. The plant residue increases the aromatic carbon at rates of 4.6, 6.4, and 9.3% under natural rainfall, water deficit, and excess water conditions, respectively. Studying the three water conditions, it could be shown that under a water deficit or excess water condition, both chicken manure and crop residues are unfavorable to POC stability; cow manure is conducive to POC stability only under excess water condition. Leaves, therefore, serve as the optimum amelioration material.