Restoring fertility to soils after topsoil stripping for brick production in Bangladesh through harnessing agro-ecosystem waste-streams.

在孟加拉国毗邻城市中心的农业区，表土剥离现象非常普遍。由于孟加拉国的城市中心呈指数级增长，特别是在本研究的重点达卡特大城市周围，人们对农业用地的丧失以及周围表土被移走的农业用地退化造成的粮食安全感到关切。据估计，印度次大陆城市周边地区因表土剥离而受到影响的土地面积为10%。去除表土后留下的底土的作物产量，即使过量施肥，也会减少50%以上，影响到自给农民。由于土壤中的粘土是建筑材料的唯一来源，孟加拉国不太可能停止或减少剥离土壤用于制砖的做法，因此非常需要找到恢复受影响土壤肥力的方法。我们建议通过利用孟加拉国农业生态系统中常见的营养丰富的农业废弃物流来实现这一目标，以迅速恢复受影响的土壤以充分发挥种植潜力。这些营养丰富的废物流包括粪肥、油饼、稻壳和生物质灰。该赠款提案计划优化如何将这些废物流应用于底土，以充分恢复土壤的可持续性，对农民来说成本较低，从而提高该地区的粮食安全。该提案分为两个阶段。第一个是确定流经孟加拉国物质稻米种植社区的废物流的营养成分和数量，然后尽可能地将这些废物流重新引导回土地。第二个项目是在孟加拉国9个地理上分散的村庄，通过湿季和旱季水稻种植，试验利用这些废物来建立土壤健康和增加水稻产量，测试孟加拉国的常见水稻品种。

The striping of topsoil is very common in the agronomic regions abutting urban centres in Bangladesh. As urban centres have been growing exponentially in Bangladesh, particularly around the mega-city of Dhaka, the focus of this study, there are concerns regarding food security due to loss of agricultural land, and the degradation of surrounding agronomic land that has had its topsoil removed. Estimates for the amount of land impacted in peri-urban zones of the Indian-sub-continent through topsoil stripping are 10%. Crop yields from the subsoils left after topsoil removal, even with excess fertilization, decrease by over 50%, impacting subsistence farmers. As clay from soil is the only source of building material, it is unlikely that the practice of stripping soils for brick production will stop or decline in Bangladesh, thus there is a great need to find ways of restoring fertility to impacted soils. We proposed to do this by harnessing nutrient rich agronomic waste streams that are common in Bangladesh agri-ecosystems to rapidly restore impacted soil to full cropping potential. These nutrient rich waste streams include manures, oil cake, rice husks & biomass ash. The grant proposal plans to optimise how these waste streams can be applied to subsoils to fully restore soil sustainability, at a low cost to the farmer, & thereby enhancing the food security of the region. The proposal has two stages. The first is to characterize the nutrient content and quantity of waste streams flowing through Bangladeshi substance rice farming communities and then maximize ways in which to redirect these waste-streams back to the land. The second is to trial, through both wet and dry season rice cultivation, across 9 geographically separated Bangladeshi villages, the utility of these wastes for building up soil health and increasing rice yields, testing common Bangladeshi rice cultivars.