Soil Respiration in Response to Different Ridge/Furrow Ratios and Its Relationship with Soil Moisture and Temperature Under Ridge-Furrow Planting Patterns

Abstract

This study aimed to explore soil respiration in response to soil moisture and soil temperature subjected to different ridge/furrow ratios under various planting patterns. Traditional flat planting and three different ridge-furrow plantings with altering ridge/furrow ratios, i. e. 20:40 cm (P40); 30:30 cm (P30); 40:20 cm (P20), were performed in the present study. Soil respirations among different planting patterns were compared. Their relationships with soil moisture and soil temperature were also analyzed. The results showed that soil respiration flux of four planting patterns reached its minimum value during the wintering stage, started to rise during the returning green stage until it reached a peak value at the flowering stage, and decreased gradually when reaching the maturity stage. The magnitude of soil respiration flux in three ridge-furrow planting patterns followed this order: P40 > P30 > P20, which implied that increasing ridge width could improve soil respiration by 1.2%-18.4%. In addition, soil respiration fluxes of three ridge-furrow plantings patterns were significantly higher than those under conditional patterns during the seedling stage (P<0.05). The soil temperature of ridge-furrow planting patterns was higher than that of the conditional flat pattern from the seeding stage to the wintering stage, but was converse from the jointing stage to the maturity stage. Moreover, three ridge-furrow planting patterns have shown significant effect on preserving soil water storage in comparison with the conditional flat pattern. In general, increasing the width of the ridge increased soil water storage due to less rainfall from the seedling stage to the jointing stage. The correlation analysis indicated a positive and significant correlation coefficient between soil respiration and soil temperature (P<0.01). Correlation coefficients in case of P40 and P30 were higher than those in P20 and the conditional flat pattern. The quadratic model of two-factor soil moisture and soil temperature could explain 61.7%-74.1% of variations in soil respiration. The single factor of the soil temperature model could explain 50.3%-68.2% of variations in soil respiration. Those results could provide a theory basis for further evaluation of ecological effect on the ridge-furrow planting patterns.