Effects of pest and soil management systems on weed dynamics in potato

• Published in: Weed science 1998-03, Vol.46 (2), p.238-248
• Main Authors: Gallandt, Eric R., Liebman, Matt, Corson, Sue, Porter, Gregory A., Ullrich, Silke D.
• Format: Article
• Language: English
• Subjects: AGRICULTURA DE BAJO INSUMO; AGRICULTURE FAIBLE NIVEAU INTRANTS; AMENDEMENT ORGANIQUE; APPLICATION RATES; AVENA SATIVA; BANCO DE SEMILLAS DEL SUELO; BIOLOGICAL COMPETITION; BIOMASA; BIOMASS; BIOMASSE; CHENOPODIUM; CHENOPODIUM ALBUM; Clover; COMPETENCIA BIOLOGICA; COMPETITION BIOLOGIQUE; COMPETITIVE ABILITY; Crop management; Crop rotation; CROP YIELD; CROPPING SYSTEMS; CULTIVATION; CULTIVO; DESHERBAGE; DOSE D'APPLICATION; DOSIS DE APLICACION; ECHINOCHLOA FRUMENTACEA; ENMIENDAS ORGANICAS; ESCARDA; FERTILIDAD DEL SUELO; FERTILITE DU SOL; GESTION DU SOL; GRAINE; HERBICIDAS; HERBICIDE; HERBICIDES; HORDEUM VULGARE; INTEGRATED CONTROL; LOSSES; LOW INPUT AGRICULTURE; LUCHA INTEGRADA; LUTTE INTEGREE; MAINE; MALEZAS; MANEJO DEL SUELO; MAUVAISE HERBE; NUTRIENT SOURCES; NUTRIENTES; NUTRIENTS; ORGANIC AMENDMENTS; PERDIDAS; PERTE; Pest control; PISUM SATIVUM; PRATIQUE CULTURALE; RENDEMENT; RENDEMENT DES CULTURES; RENDIMIENTO; RENDIMIENTO DE CULTIVOS; ROTACION DE CULTIVOS; ROTATION CULTURALE; ROTATIONAL CROPPING; SEEDS; SEMILLA; SISTEMAS DE CULTIVO; SOIL FERTILITY; SOIL MANAGEMENT; Soil resource management; SOIL SEED BANKS; SOLANUM TUBEROSUM; STOCK SEMENCIER DU SOL; SUBSTANCE NUTRITIVE; Sustainable agriculture; SYSTEME DE CULTURE; TRIFOLIUM PRATENSE; VICIA VILLOSA; WEED CONTROL; Weed Management; WEEDS; YIELDS
• ISSN: 0043-1745; 1550-2759
• DOI: 10.1017/S0043174500090482

Results from the “Potato Ecosystem Project,” a cropping systems study in northern Maine, were used to test the hypothesis that greater reliance on organic nutrient sources and less reliance on synthetic fertilizer sources can benefit weed management efforts. ‘Atlantic’ potato was grown in a 2-yr rotation within a factorial arrangement of three pest management systems, two soil management systems, and both rotation entry points. Weed control in the conventional (CONV) pest management system relied on full rates of herbicides, whereas the biointensive (BIO) system relied exclusively on cultivation. The reduced input (RI) pest management system relied on cultivation in 1991 and 1992 and on 50% of standard herbicide rates plus cultivation from 1993 to 1995. The two soil management systems, unamended (barley/red clover rotation crop; 1× synthetic fertilizer for potato) and amended (pea/oat/hairy vetch green manure rotation crop; manure, compost, and 0.5× synthetic fertilizer for potato) contrasted practices typical for the region to those designed to achieve rapid improvements in soil quality. Midseason weed biomass in potato was dominated by common lambsquarters. In 1991 and 1992, weed biomass in potato was least in the CONV system and did not differ between the RI and BIO systems. In 1993, weeds in both RI and CONV potatoes were effectively suppressed below the level measured in the BIO system. Soil management had no effect on weed biomass from 1991 to 1993 but became an important factor affecting weeds in the BIO system in 1994 and 1995. Weed biomass was 77% lower in 1994 and 72% lower in 1995 in the amended soil management system than in the unamended system. No significant yield loss due to weeds was detected in the 1994 BIO system, but in 1995 yield loss due to weeds was 37% in the unamended system compared to 12% in the amended system. Soil management effects on weeds in the 1994 BIO pest management system carried through to the following season's germinable seed bank. Density of germinable common lambsquarters seed (0 to 10 cm soil depth) in the 1995 BIO system was 4,082 m−2 in the unamended soil management system compared to 1,280 m−2 in the amended soil management system. We suggest that organic amendments and green manure promote a potato crop better able to compete with weeds and that these inputs be considered as potentially important components of integrated weed management systems that have minimal reliance on herbicides.