Effects of grain-producing cover crops on rice grain yield in Cabo Delgado, Mozambique

ABSTRACT Besides providing benefits to the environment such as soil protection, release of nutrients, soil moisture maintenance, and weed control, cover crops can increase food production for grain production. The aim of this study was to evaluate the production of biomass and grain cover crops (and its respective effects on soil chemical and physical attributes), yield components, and grain yield of rice in Mozambique. The study was conducted in two sites located in the province of Cabo Delgado, in Mozambique. The experimental design was a randomized block in a 2 × 6 factorial, with four repetitions. Treatments were carried out in two locations (Cuaia and Nambaua) with six cover crops: Millet (Pennisetum glaucum L.); namarra bean (Lablab purpureus (L.) Sweet), velvet beans (Mucuna pruriens L.), oloco beans (Vigna radiata (L.) R. Wilczek), cowpea (Vigna unguiculata L.), and fallow. Cover crops provided similar changes in chemical and physical properties of the soil. Lablab purpureus, Vigna unguiculata, and Mucuna pruriens produced the highest dry matter biomass. Vigna unguiculada produced the highest amount of grains. Rice grain yields were similar under all cover crops and higher in Cuaia than Nambaua.

摘要：覆盖作物（cover crops）除可发挥土壤保护、养分释放、维持土壤水分及杂草防控等环境效益外，还可提升谷类生产的籽粒产量。本研究旨在评估莫桑比克境内覆盖作物的生物量与籽粒产量（及其对土壤理化属性的影响）、水稻产量构成因子及籽粒产量。试验设于莫桑比克德尔加杜角省的两个试验点，采用2×6因子设计的随机区组设计，设置4次重复。试验设置两个地点（库阿亚Cuaia与南巴瓦Nambaua），共6种覆盖作物作为处理：珍珠粟（Pennisetum glaucum L.）、藊豆（Lablab purpureus (L.) Sweet，即namarra bean）、毛蔓豆（Mucuna pruriens L.，即velvet beans）、绿豆（Vigna radiata (L.) R. Wilczek，即oloco beans）、豇豆（Vigna unguiculata L.，即cowpea）以及休闲处理。结果表明，各类覆盖作物对土壤理化性质的改善效果相近；藊豆、豇豆与毛蔓豆的干物质生物量最高；豇豆的籽粒产量最高；各覆盖作物处理下的水稻籽粒产量无显著差异，但库阿亚试验点的水稻籽粒产量高于南巴瓦试验点。