Feed the Future
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Climate-Smart Soil, Water and Nutrient Management

This post was written by Emily S. Weeks. Emily is a Natural Resource Management and Policy Specialist and AAAS Science and Technology Policy Fellow in the USAID Bureau for Food Security Policy Division, Office of Agricultural Research & Policy.

Healthy soils and appropriate land use underpin sustainable primary production and contribute to the ability to neutralize greenhouse gas emissions. Knowing the status and condition of soils and their properties is fundamental for making decisions about sustainable management practices that contribute to climate-smart land use. Soils that are degraded are at much greater risk from the damaging impacts of climate change, and land degradation itself is linked to climate change.

One of the primary functions of soil is to capture precipitation, storing water for plants to use at a later day. Essentially it is the plant's water and nutrient bank account. Each soil has different water storage quality, depending on organic matter levels, soil texture and structure. Some soils will have a high water storage bank, whilst others store much less. The ease by which plants can withdraw water from their soil water storage bank varies greatly between different soils. Once the soil water storage bank is full, excess precipitation either moves to the surface as run-off, or percolates down through soil as drainage into groundwater.

Unsustainable farming practices, deforestation, and overgrazing lead to the destruction of soil-holding plants. Erosion of top soil by water or wind removes vital plant nutrients from topsoil and adds excess plant nutrients to aquatic systems—degrading topsoil and polluting water. This also disrupts nitrogen, carbon, and phosphorous cycles. Reducing topsoil erosion is an important component of climate smart agriculture.

Climate-smart soil management involves a variety of methods to reduce topsoil erosion. With the help of ongoing research, farmers can adopt climate-smart practices that not only help reduce topsoil erosion and restore soil fertility, but also control nutrient run-off. Current erosion assessment and mitigation efforts are focused on investigating erosion processes and identifying sources.

Scientists are developing new methods to fingerprint the sources of sediments, study sediment dynamics, and assess the stabilizing characteristics of plants. Equally important is research into the myriad of processes that soil water influences, ranging from the availability of nutrient’s for plant uptake to processes that determine soil’s ability to filter contaminants. Based upon this platform of fundamental knowledge, scientists are actively working towards developing good management practices and decision support tools to increase the efficiency of soil water storage, and resultant plant use, whilst decreasing nutrient and contaminant leakage from soil into waterways. 

Read more: https://ccafs.cgiar.org/blog/climate-smart-soil-water-and-nutrient-management-options-semi-arid-west-africa#.VzDptfkrI7U