Using high-residue cover crop mulch for weed management in organic no-till potato production systems

R. Morse

Abstract
Weed management is considered the most challenging production problem facing organic farmers. Without effective herbicides, organic growers normally rely on hand weeding and multiple cultivations, which can be expensive, time consuming and degrade soil quality.

Applying thick layers of organic mulch can control weeds; however, this practice is normally cost-prohibitive. Although equally challenging, organic no-tillage (NT) systems offer cost effective improvements in both weed management and soil quality. This paper highlights recent research (2002-2004) funded by the Organic Farming Research Foundation on organic NT potatoes (Solanum tuberosum L.) and includes relevant data from past NT potato studies (1995- 2001).

Based on these data (1995-2004), high-residue raised-bed NT systems are a viable option for producing organic potatoes, particularly in warm long-season climates. Success is most likely achieved in climates and situations where high-residue mulch favorably impacts the growing environment of the potato crop—e.g. suppression of weeds and pests (e.g. Colorado potato beetle), moderation of soil temperature, increased plant-available water and nutrients, and improved soil quality.

Recommended best-management practices arising from these studies
include (1) erecting and nutrient loading (soil building) raised beds before seeding cover crops; (2) drilling high-residue grass-legume mixtures on raised beds--e.g. rye/hairy vetch and barley/hairy vetch; (3) achieving high soil tilth in in-row areas (grow zones) by using potato planters equipped with a wide-wing subsoil shank; and (4) post-plant killing cover crops (2-3 wk after planting potato seed pieces). Suggestions are also given for using strip-till methods in field and climatic situations not suitable for high-residue NT systems

Source
http://ofrf.org/funded/reports/morse_03s18.pdf


Author Locations & Affiliations
Virginia Tech
Department of Horticulture
306-C Saunders Hall
Blacksburg, VA 24061


Posted March 2010