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Submitted to: American Journal of Alternative Agriculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/3/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Dryland regions of the Pacific Northwest need conservation tillage to control water erosion, but adoption has been slow because crop yield is frequently less than where conventional practices are used. Landscapes are much more sloping, much more irregular, and face in alldirections, which creates a multitude of micro-environments in which young seedlings must grow. Surface mulches in cold wet conditions increase soil-borne plant disease, promote weed infestation, impede tillage implements, and alter plant nutrient availability. No one yet knows how to alleviate all of these adverse factors. Fertilizer placement plus slight alteration in the nutritional level increases cereal performance in conservation tillage. Plant access to nutrients increases when fertilizers are banded below the residue layer and quite close to the seed. Weed competition is less. Soil disturbance below the seedling when fertilizing also decreases disease pressure. But with all of these improvements, we have not always been able to achieve equal yield over the entire field. We now need better methods to protect young seedlings from soil-borne plant pathogens in the spring of the year and to better identify which portions of the landscape need conservation tillage. Technical Abstract: Dryland regions of the Pacific Northwest need conservation tillage to control water erosion, but adoption has been slow because crop yield is frequently less than where conventional practices are used. Landscapes are much more sloping, much more irregular, and face in all directions, which creates a multitude of micro-environments in which young seedlings must grow. Surface mulches intensify soil-borne plant diseases, promote weed infestation, impede tillage implements, and alter plant nutrient availability. Different fertilizer practices were implemented in conservation tillage to investigate soil fertility¿s role in solving the problem. Fertilizer placement plus slight alteration in the nutritional level increases cereal performance in conservation tillage. Plant access to nutrients increases when fertilizers are banded below the residue layer and quite close to the seed. Weed competition is less. Soil disturbance below the seedling when fertilizing also decreases disease pressure. But improvements in fertilization practices alone have not always been able to achieve equal yield over the entire field. We now need to identify which portions of the landscape need conservation tillage, and develop better methods to protect young seedlings from soil-borne plant pathogens in the spring of the year on certain landscape positions. |
