Litter Decomposition Characteristics and Variety Differences in a Kiwifruit Orchard in Subtropical Climate Zone of China

Abstract

The aim of this study was to reveal the decomposition dynamics of kiwifruit litter and verify the variety differences and provide a scientific basis for rational fertilization in orchard. Kiwifruit litters of two varieties (‘Hongyang’ and ‘Jinyan’) were taken as the objects; the litter decomposition rate, the dynamics of macro-elements and micro-elements, and soil enzyme activities during the decomposition process were analyzed. The results showed that the litter decomposition rate of ‘Hongyang’ kiwifruit was faster than that of ‘Jinyan’ kiwifruit, because of the higher initial N and P content in the litter of the ‘Hongyang’ kiwifruit. The dynamic trends of macro-elements and micro-elements during litter decomposition of two varieties were similar. The C content was relatively stable, the P content was fluctuant, and the K content was decreasing. The contents of N, Fe, Mn, Cu, and Zn were increasing. The contents of Ca, Mg, and B increased first and then decreased. After 180 days of the decomposition experiment, more than 75% of the initial contents of C, N, P, K, Ca, Mg, and B were released. The dynamic trends of the soil enzyme activities of two varieties were generally similar. Due to the slow decomposition rate, the dynamic trends of soil enzyme activities of ‘Jinyan’ kiwifruit litter each showed hysteresis. The contents of Ca, Mg, and Mn were significantly correlated with some soil enzyme activities. In conclusion, the litter substrate quality of the two kiwifruit varieties is different, which leads to the difference in the decomposition rate. The litter decomposition of kiwifruit is an important supplement to the macro-element in orchard soil.

Litter Decomposition of Two Kiwifruit Cultivars (‘Jinkui’ and ‘Hort-16A’) with Different Litter Qualities in the Orchard Ecosystem

“…The litter decomposition rate was calculated by the Olson's model (exponential decay model) [26]. This model was fitted based on litter residual rate and decomposition time, and the equation of model was as follows:…”

“…According to the methods in Trinsoutrot et al [25], the concentrations of C and N were determined by the element analyzer (vario MACRO cube, Germany Elementar, Langenselbold, Germany). According to the methods in Lu et al [26], the concentration of P was determined by the ultraviolet spectrophotometer (UV-1800, Japan Shimadzu, Kyoto, Japan), and the concentration of K was determined by the atomic absorption spectrometer (Analyst 800, USA PE, Cincinnati, OH, USA).…”

“…We ground the soil and sifted it with the soil sieve (diameter of 0.25 mm). According to the methods in Lu et al [26], the activities of soil enzymes were determined by the ultraviolet spectrophotometer (UV-1800, Japan Shimadzu). Specifically, the activities of sucrase were determined by 3,5-dinitrosalicylic acid colorimetry.…”