Toward cropping systems that enhance productivity and sustainability

Abstract

The defining features of any cropping system are (i) the crop rotation and (ii) the kind or intensity of tillage. The trend worldwide starting in the late 20th century has been (i) to specialize competitively in the production of two, three, a single, or closely related crops such as different market classes of wheat and barley, and (ii) to use direct seeding, also known as no-till, to cut costs and save soil, time, and fuel. The availability of glyphosate-and insect-resistant varieties of soybeans, corn, cotton, and canola has helped greatly to address weed and insect pest pressures favored by direct seeding these crops. However, little has been done through genetics and breeding to address diseases caused by residue-and soil-inhabiting pathogens that remain major obstacles to wider adoption of these potentially more productive and sustainable systems. Instead, the gains have been due largely to innovations in management, including enhancement of root defense by antibiotic-producing rhizosphere-inhabiting bacteria inhibitory to root pathogens. Historically, new varieties have facilitated wider adoption of new management, and changes in management have facilitated wider adoption of new varieties. Although actual yields may be lower in direct-seed compared with conventional cropping systems, largely due to diseases, the yield potential is higher because of more available water and increases in soil organic matter. Achieving the full production potential of these more-sustainable cropping systems must now await the development of varieties adapted to or resistant to the hazards shown to account for the yield depressions associated with direct seeding.

Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110

“…In western Kansas, both dryland yields and annual precipitation exhibit stationary trends over the past 30 y. Although recent no-till dryland farming practices have higher yield potential than conventional cropping systems as the result of more available water and increases in soil organic matter, the actual yields may be lower because of diseases (31). Note that dryland yields do not account for unharvested fields due to failed crops during dry years or for fields that went unplanted because of low subsoil moisture during planting time.…”

Understanding and Enhancing Soil Biological Health: The Solution for Reversing Soil Degradation

“…The health of the soil biota is strongly linked to the resistance of soils to erosion. Soil biological diversity is positively linked to ecosystem level processes such as C and nutrient dynamics [69] and has a central role in agroecosystems that are operated in an environmental-and economically-sustainable manner [217,218]. Soil biology is the key to ensuring the ability to "Feed the World" [219] and reversing the degradation of soils that support crop production.…”

Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.)

“…Such concerns have led to the search for tillage systems that minimize negative impacts to the environment while sustaining economic crop productivity. Conservation tillage techniques, including minimum tillage and notillage, minimize the impact on soil structure and on soil biota (Cassiolato et al 2001, Cook 2006, and may help reduce CO2 emissions in comparison to traditional tillage (Hernanz et al 2009). To address these concerns, conservation tillage systems need to be adopted and implemented in crop production systems.…”