Farming for Resiliency at the NS/S Conservation Farm
By Lynda Prim, NS/S Conservation Farm Manager. Published on May 18, 2015.
Farming systems all over the world are facing complex problems in terms of food production related to natural resource depletion, climate change, and increasing food demand. In order to deal with the future of producing food on our planet, farmers will need to adapt to continuously changing conditions while taking steps to make their farming systems resilient in a changing climate.
At the NS/S Conservation Farm, we are working on improving the resilience of arid land agriculture to climate change. At the center of our work is growing seeds to conserve the biodiversity that is a critical part of a more resilient agriculture. We are developing a farming system for growing seeds and food in arid lands by doing research and demonstration of tools and practices designed for adaptation to climate change. These include traditional indigenous farming practices such as terrace and waffle beds, cover crop management, water conserving irrigation methods, soil building, and enhancing natural biodiversity in the farm landscape. To accomplish this, we are acquiring the farming tools and implementing methods for balancing agricultural production with conservation and ecosystem services such as a reciprocating spader for tilling the soil, an overhead irrigation system to replace flood irrigation, and planting pollinator and beneficial insect habitat. While the NS/S Conservation Farm is focused on the technological design of arid land farming systems, we are doing so with an awareness of cultural factors and of global issues such as food security, climate change, biodiversity, and socio-economic development.
One of the effects of climate change is increasing drought. Drought is predicted to become widespread globally and is already a problem for farmers in the Southwest region. Water use tends to increase as crop yields increase — and with the world’s population expected to increase by 33% in the next 35 years, water deficits are likely. In order to buffer farms against water shortages farmers can work with the soil and water balance on their farm by:
- increasing the ability of plants to extract more water from the soil;
- decreasing soil water loss through evaporation;
- increasing the capacity of the soil to hold more water; and
- adapting their cropping system.
The evapotransporation rate (soil water evaporation + plant transpiration) is a key factor. Some components of evapotransporation involve climate factors farmers can’t control, such as the sun’s radiant energy, water vapor temperatures, and wind speed. But farmers can control soil water availability to some extent with their management practices. Reducing tillage lowers moisture loss to the atmosphere. Maintaining a cover crop or crop residue layer over the soil surface will decrease evaporation by 50% to 80% compared to a tilled soil because the cover crop or crop residue creates a microclimate near the soil surface that is less conducive to evaporation.
Cover crops are central to conservation farming and they are our primary source of soil fertility and mulch on the NS/S Conservation Farm. Research is documenting that where crops are planted into stands of cover crops or crop residue water use efficiency increases by about 30%. Plants also show larger leaves and more rapid growth from being sheltered from the wind and reduced water stress. There is also research showing that the use of high-disturbance tillage, cultivation, and seeding equipment can more than double the loss of carbon and water from soils when compared to low-disturbance tillage equipment, such as our new spader. There can be differences in soils on a farm and even within a field related to organic matter content and soil water-holding capacity, but this variability can be mitigated over time by enhancing soil quality at the field level. For this reason, the NS/S Conservation Farm is embarking on a program of assessing soil conditions and examining how our farming system — tilling and cultivation, soil cover, seeding, and irrigation — can conserve soil fertility and water. At the same time we are looking at the role that the crop genetic diversity we are conserving plays in developing a resilient farming system that can help contribute new farming traditions for the future of agriculture.