农民创新：通过土地和水管理改善非洲的粮食安全

This post is part of WRI's blog series,Creating a Sustainable Food Future。该系列探讨了到2050年到2050年可持续养活超过90亿人的策略。2013-2014世界资源报告。

The nature of agriculture is changing. Farmers across the world struggle to produce more food while facing changing rainfall patterns, a warmer world, and increased competition over land and water. Ecosystem degradation, declining soil fertility, and water stress add to these land use pressures.

这些挑战比撒哈拉以南非洲的旱地更为严重。旱地地区的农民必须像干旱，不可预测的降雨和土壤养分耗尽。同时，撒哈拉以南非洲是世界上最贫穷的地区之一。Roughly 200 million people—a full 27 percent of the population—are undernourished.Forty percentof children under the age of five are stunted due to malnutrition.

但是，尽管挑战是伟大的，但机会也是如此。创新的农民已经证明了农林业和其他相对简单的做法如何显着促进非洲旱地的粮食生产。实际上，according to a new WRI working paper，改善撒哈拉以南非洲3亿公顷的主要农田的土地和水管理将导致2200万吨食品。这种策略可能会为可持续的养活非洲和世界提供很长的路要走。

Farming in Africa’s Drylands

Sub-Saharan African farmers have been fighting drought and land degradation for years. In response, a growing numberare starting to adopt改善了土地和水管理实践，以减少侵蚀，捕获更多的降雨量，增加土壤有机物并补充养分。他们的令人鼓舞的结果为恢复农田生产率并为人口增长的粮食提供足够的食物所需的策略类型提供了教训。改善了土地和水管理实践，例如agroforestry, conservation agriculture, rainwater harvesting, and integrated soil fertility management are sustainably increasing crop yields while also reducing agriculture’s impact on the environment.

For example:

• Farmers in Burkina Fasoand Niger are using water-harvesting techniques such as building stone lines and improved planting pits (locally known asZai). These practices help to trap rainfall on crop fields, increasing average cereal yields from 400 to 900 kilograms per hectare (kg/ha) or more. Applying small quantities of fertilizer directly to seeded crops or young shoots early in the rainy season can complement these low-tech land and water management techniques. Combining this “micro-dosing” with practices like water-harvestinghas increased小米和高粱的产量从不到500 kg/ha到1,000或1,500 kg/ha。

• 马拉维的农民正在种植Faidherbia albidatrees on fields using modest amounts of fertilizer. These trees provide canopies of shade and lock nitrogen in the soil. Farmers have seen their maize crop yieldsincreasefrom fewer than 2 tons per hectare to 3 and 4 tons per hectare . Yields are more than 7 tons per hectare when these conservation agriculture practices are combined with agroforestry, fertilization, and other strategies.

• 在西非，农民通过施用农作物，堆肥，覆盖物，牲畜，叶子和肥料来采用综合土壤肥力管理。这些实践有助于农民满足农作物的营养需求，同时恢复土壤有机物和整体土壤肥力，这有助于可持续的作物生产。超过200,000公顷的土壤生育能力综合管理结果in crop yield increases of 33-58 percent over a four-year period. Farmers also saw revenue increases of 179 percent from maize and 50 percent from cassava and cowpea.

More Action Is Needed

尽管有改善的土地和水管理以及一些重大成功的好处，但这些策略的总体采用仍然太有限，无法对非洲的粮食安全产生重大影响。一些常见的障碍包括缺乏对适当做法及其利益的认识，以及在知识传播方面的投资水平较低。由政府，非政府组织和其他人开展的农业项目常常无法与农民互动，或者有效地传播有关如何完成雨水收集，农林业和其他实践的信息。农业推广代理人根本无法接触到无数的农民，而在这里确实存在延期，农林业，保护农业和其他实践不足以融合。在许多情况下，国家政策和立法没有提供足够的激励措施，例如赋予公民对土地的合法所有权和清晰的农业树木的权利，以鼓励农民投资改善的土地和水管理。

Additionally, many decision-makers tend to focus on more “high-tech” solutions to increasing food production—strategies like increased subsidies for mineral fertilizers, promotion of improved seeds, and agricultural mechanization. But the potential benefits of these approaches will be undermined unless the depletion of soil fertility is reversed and climate change impacts are overcome.

非洲旱地越来越多的农民are already showing us the benefitsof improved soil and water management. Now it’s time to scale up these practices to make widespread, significant, and sustained gains in crop yields.

• LEARN MORE：WRI的第四期World Resources Report建议采用七种方法，以加快验证，成本效益的土地和水管理实践的扩展。Download the full paper。