Submitted to: Proceedings Washington State Potato Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/6/2003
Publication Date: 3/25/2003
Citation: COLLINS, H.P., PIERCE, F., BOYDSTON, R.A., GRUNWALD, N.J., MUNYANEZA, J.E. ADOPTING CONSERVATION TILLAGE IN IRRIGATED CROPPING SYSTEMS. 42ND ANNUAL WASHINGTON STATE POTATO CONFERENCE PROCEEDINGS, FEB. 2-6,2003, MOSES LAKE, WA, WASHINGTON STATE POTATO COMMISSION, P. 81-92. 2003. Interpretive Summary: Tillage in most crop rotations is practiced to prepare seed-beds, control weeds and other pests, manage crop residues, reduce soil compaction, and incorporate fertilizer and pesticides. However, excessive tillage increases soil erosion, reduces soil carbon, decreases beneficial organisms, increases fuel and labor needs, and reduces soil moisture. Growers that have implemented reduced tillage generally do so for two basic reasons: 1) to improve soil and water conservation and 2) to reduce costly inputs and improve profits. Limitations to adoption of reduced tillage in many cropping systems have been poor crop stands due to cool soils, disease and pest problems, and poor soil seed contact; poor weed control; inability to manage crop residues; inability to incorporate fertilizers and pesticides; and cost to replace existing equipment. Developments in low till or no till seeding equipment and field implements that handle crop residues and improved herbicide and fertilizer formulations have made it possible for growers to practice reduced tillage. Success of reduced till vegetable production systems is dependent on adoption of effective weed control strategies, modifications to nutrient delivery, and pest management.
Technical Abstract: Tillage in most crop rotations has been used to prepare seed-beds, control weeds and other pests, manage crop residues, reduce soil compaction, and incorporate fertilizer and pesticides. However, excessive tillage increases soil erosion, reduces soil carbon, increases fuel and labor needs, and reduces soil moisture. Conservation tillage systems are designed to manage crop residues on the soil surface with minimum or no-tillage. Systems are commonly referred to as stubble mulching, eco-fallow, reduced tillage, minimum tillage, no-tillage and direct seed. The goal of these systems is to maintain sufficient residue on the soil surface to reduce wind and water erosion, reduce energy use, conserve soil and water resources, reduce costly inputs and improve profits. Increasing concern about the sustain-ability of irrigated crop production systems and environmental quality has emphasized the need to develop and implement management strategies that maintain and protect soil, water and air resources. Production in irrigated regions typically occurs on soils low in organic matter that are highly susceptible to agri-chemical leaching under poor irrigation scheduling, and wind erosion when soils are left fallow. Adopting conservation tillage to reduce erosion, increase N use efficiency, and build organic matter would improve soil and environmental quality under irrigated farming systems. The purpose of this review is to present a discussion of conservation tillage and identify where conservation tillage may fit into irrigated cropping systems.