Effect of Soil Moisture Evaporation Control by Organic Material Mulching

摘要

There are many semi-arid and arid areas in the world, but Africa, particularly Sub-Saharan Africa, is one of the most vulnerable regions under the threat of desertification. This problem isfurther compounded by insufficiency in agricultural water use and declining soil fertility. In this study, the following test was conducted with the objective of contributing to agricultural production in the region by utilizing locally available organic material mulches in controlling soil moisture evaporation. i ) The evaporation control test was carried out in three columns made of PVC with each column consisting of three different treatments, namely organic material mulching with sorghum stalk residues, lumber chips and non-mulching. The amount of evaporation from the reduced mass was determined for each of these treatments. ii) Upland rice was cultivated at each plot of 6.5 m long and 0.8 m wide. Four plots were divided into 2 groups based on the amounts of irrigation ; one was irrigated at 3 to 6 mm/day (Standard plot) and the other at 1.5 to 3 mm/day (1/2 water saving plot). Each group was constituted with 3 different treatments as organic material mulching with sorghum stalk residues, lumber chips and non-mulching. Soil moisture was measured by TDR soil moisture sensor, and the impact on plant growth monitored. Results of both experiments showed that evaporation from the organic material mulching with sorghum stalk residues and lumber chips were smaller than non-mulching. Organic material mulching test plots with sorghum stalk residues showed remarkable results. In addition, it became clearer that organic material mulching plots were better than those that were not mulched in terms of their potential effectiveness in promoting early growth and heading of upland rice.