Open Access

ARTICLE

Optimization of Organic Mulches Thickness Improves Soil Moisture Retention under Controlled Conditions

Jiayi Zhang¹, Guohua Fu², Zhiyang Jin³, Lihang Chi¹, Guocheng Xu¹, Daran Yue^1,*

1 Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Engineering Research Center of Rare and Precious Tree Species in Hainan Province, College of Forestry, Hainan University, Haikou, 570228, China
2School of Management, Hainan University, Haikou, 570228, China
3 Mechanical and Electrical Engineering College, Hainan University, Haikou, 570228, China

* Corresponding Author: Daran Yue. Email:

(This article belongs to this Special Issue: The Effect of Soil Quality Degradation on the Plant Growth, Quality and Food Safety in Subtropical Agroforestry Ecosystems)

Phyton-International Journal of Experimental Botany 2022, 91(4), 841-857. https://doi.org/10.32604/phyton.2022.017938

Received 18 June 2021; Accepted 14 September 2021; Issue published 09 December 2021

Abstract

Organic mulch can improve the moisture, chemical composition, dust, and dust suppression of soil, and beautify the environment. In view of the rapid evaporation rate and serious loss of soil water in tropical areas, this paper explored the effect of organic mulch materials with different thickness on the increase of soil water retention rate and the improvement of soil water loss caused by evaporation. Rubberwood sawdust (RWS), rubberwood bark (RWB), coconut fiber (CF), and Mulch (MC) were selected as the mulching materials. Field experiment and laboratory experiment were performed, and soil-moisture content and temperature were continuously monitored. However, from the daily measurement of water content at constant conditions (29°C ± 0.2°C, 74% ± 1% air RH) in the laboratory experiment, the results of variance analysis (ANOVA) showed that there was no significant difference between the soil-water content of covered samples and bare soil (P > 0.05). In the field experiments, the analysis of variance indicated significant differences in the soil-moisture content owing to the effect of the covering material (P < 0.01). Mulching increased the soil-moisture content with smaller fluctuations in the deep soil compared with bare soil. The most stable soil-moisture content were achieved by RWS, RWB, CF, and MC, with thicknesses of 5, 3, 7, and 5 cm, respectively, compared with bare soil, and the average water contents of the 0–40 cm soil layer was 0.58%, 0.01%, 0.82%, and 0.93%, respectively. Vertically, the intensity of the change in soil moisture decreased gradually with increasing depth, and was more stable than that of bare soil and other treatments. Among them, the difference in water content between the adjacent gradient soil layers (the soil layers are graded every 10 cm in depth) M_3–7 (0.011 ± 0.004) was the smallest. It can be concluded that CF mulching materials with a thickness of 7 cm would be preferable when selecting mulching materials for controlling soil moisture in tropical cities.

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