FAQ - Croplands

What is climate-smart agriculture?

Climate-smart agriculture (CSA) is an approach that helps agricultural systems to develop sustainable food production under climate change. CSA helps to guide actions needed to reorient agricultural systems towards ensuring food security in a changing climate. It also aims to sustainably increase agricultural productivity while reducing greenhouse gas emissions and increasing resilience and adaptation to climate change.

How can farmers innovate and adapt to a changing climate?

There are multiple ways farmers can innovate and adapt to a changing climate. Some of the promising technologies that can be adopted include the use of more recent crop varieties and species, adjustment in the timing of farm operations, diversified cropping systems, cover cropping, livestock-integrated cropping systems, conservation tillage systems, and more efficient irrigation, fertility, pest, and disease management practices.

How can we increase resilience through improved soil and nutrient management?

First, we need to know that soil is a living system. Healthy soil is like a healthy human being; it can function better when health and nutrition are balanced. Improved management practices that minimize disturbance, increase diversity in crop residue and nutrient inputs, and provide a consistent environment for microbial proliferation can accumulate more soil organic matter, which is a storehouse of nutrients. Soil organic matter also increases water holding capacity, pH buffering, soil aggregation and aggregate stability, and infiltration. With these positive changes, soils can function better under biotic (insect pests and diseases) and abiotic (heat and drought) stresses.

What is the role of cover crops and crop diversification in resilience efforts?

Most of New Mexico crop agriculture historically falls under one of two systems:

  • Dryland: Winter wheat–sorghum–fallow and winter wheat–summer fallow

  • Irrigated: Corn, alfalfa, wheat and a few other minor crops

Intensively tilled agricultural fields with extensive fallow in western United States decreased soil organic matter stock by 30 to 60% in the last 100 years (e.g. Ghimire et al., 2015; Thapa et al., 2018). Studies also found 3 to 57% yield reduction of major crops grown in short rotation sequences and monocultures compared to yields in diverse rotations. Low productivity in less diverse rotations was attributed to high insect pest and weed damage, soil compaction, nutrient depletion, low microbial diversity, and reduced soil water availability. Crop diversification through multispecies crop rotations and cover cropping, on the other hand, can diversify food for microbial community, and thereby augment microbial growth, maintain soil health, suppress pests, and restore organic matter. Cover cropping and crop diversification along with conservation tillage can increase soil water storage, nutrient cycling, and soil aggregation and thereby soil health and resilience. Diversification through crop rotation and cover cropping can be an especially useful strategy in farming systems that integrate cropping systems with livestock production.

To support conservation, climate mitigation, and sustainable water resources, how important is it to know about local soil, ecological, and cultural situations?

Understanding local soil, climate, and agricultural practices plays an important role in sustainable soil and water management as well as climate mitigation and carbon sequestration. According to climate change projections for the Great Plains region, expected changes in precipitation will make the Northern Great Plains wetter and the Southern Great Plains drier compared with current conditions, which increases uncertainty regarding crop production in the Southern Great Plains in comparison with other regions. Similarly, soils in the Southern Great Plains are low in fertility, making them more vulnerable to climate change. Knowledge of such delicacy of ecosystem helps farmers better manage their system to increase climate mitigation and soil water conservation. Our research in eastern New Mexico shows that integrating livestock into cropping systems (winter grazing) stored about 12% more soil organic matter and 40% more microbial mass compared to ungrazed croplands. Grasslands could store about 18% more soil organic matter than croplands.

How can farmers reduce the impact of agriculture on water quality? (Boosting irrigation efficiency; tillage practices; adaptive management)

Water availability and quality are two major issues faced by NM agriculture. Farmers can reduce the impact of agriculture on water quality by adopting conservation tillage systems that leave more crop residue on the soil surface and reduce runoff and soil erosion, conserve soil moisture, and help keep nutrients and pesticides on the field. Smart and site-specific nutrient management that accounts for all nutrient inputs ensures nutrient availability to meet crop needs and reduces nutrient loss off the fields. Improved irrigation management technologies increase water use efficiency while reducing off-farm impacts. In livestock-integrated systems, optimizing stocking density with land productivity and soil condition will help minimize soil erosion and water quality impact of animals.

References:

Thapa, V.R., R. Ghimire, M. Mikha, J. Idowu, and M. Marsalis. 2018. Land use systems effects on soil health in drylands. Agricultural and Environmental Letters. Doi: 10.2134/ael2018.05.0022.

Ghimire R., S. Machado, and K. Rhinhart. 2015. Long-term crop residue and nitrogen management effects on soil profile carbon and nitrogen in wheat – fallow systems. Agronomy Journal 107:2230-2240. DOI: 10.2134/agronj14.0601.