The Degradation Rate of Straw Returned to Limestone Soil and the Effect on Soil Fertility

Abstract Limestone soil is a poor quality soil with a low rate of nutrient supply due to the accumulation of organic carbon. Here, we examined the degradation of maize straw in limestone soil and red soil using indoor simulation. Dynamic testing was conducted on soil chemical properties and soil fertility. We found that the degradation rate of straw in karst soil is higher than for non-karst soil. The highest degradation rate of straw occurred during the first 60 d, after which it rose slowly and balanced out at 98 d. The peak value of degradation of straw in karst soil was found at 28 d, while that in non-karst soil occurred at 42 d. The total period of degradation lasted 160 d; the degradation rate of straw in karst soil and non-karst soil was 77% and 75%, respectively. During the period of straw degradation, the pH of soil tended to decrease in the early stage and rise slowly in later stages and this is consistent with the pattern of degradation products during different stages of straw degradation. St...