Restoring the Soil - Canadian Foodgrains Bank

72Green Manure/Cover Crop SystemsAsian Green Manure/Cover Crop SystemsBangladeshS65. Various crops/lablab bean. Land-hungry Bengalis often plant a few seeds oflablab beans (known there as “hyacinth beans”) right next to their houses, so the beanwill grow up and cover the roof of the house. The seeds are eaten as a pulse, and thegreenery is spread across their fields as fertilizer. Probably hundreds of thousands ofBengalis use this traditional system.ThailandS66. Citrus/mimosa. Spineless Mimosa species are grown near the town of ChiangMai as a cover crop under citrus trees. Probably only 50 to 100 people use thisintroduced system.S67. Citrus/centrosema. Centrosema pubescens is grown under citrus trees near ChiangMai as a perennial gm/cc, as well as for animal fodder. Perhaps a hundred farmers usethis system.S68. Citrus/cowpeas. Cowpeas are also grown as a cover crop under citrus. Very fewfarmers are as yet using this introduced system.S69. Maize/rice bean-2. Rice bean is relayed into maize fields a month or two beforethe maize is harvested. Then the rice bean continues to grow throughout much of thedry season. The rice bean is grown partly to fertilize the soil, partly to produce therice beans as a cash crop, and partly to keep the soil covered during the dry season forbetter weed suppression and protection of the soil. The system also reduces the loss ofsoil nitrogen and, in many cases, allows farmers to use zero tillage (reducing costs onceagain). 28 Two or three hundred farmers use this system that was recently developed byfarmers.S70. Maize/cowpea-2. The cowpea is relayed into maize, as is done with the rice beanin S69. Most of the same farmers who use S69 also use this one, just alternatingbetween one legume and another in different years.S71. Maize/lablab bean-3. The lablab bean is relayed into maize, just as it is done withrice bean in S69 (Photo 28). Two or three hundred farmers use this system.LaosS72. Upland rice/pigeon pea. Pigeon pea (Cajanus cajan) is planted at the same timeas upland (non-irrigated) rice, at a rate of about one seed every 1.5 to 2 m in eachdirection. Thousands of farmers use this traditional practice in northern Laos.28Prinz, Klaus and Somchai Ongprasert, “Relay Cropping as an Improved Fallow in Northern Thailand”, Unpublished.