Crop and weed response to reduced fertilization and tillage system in rainfed cereal crops

Abstract

Se muestran diversos resultados obtenidos durante 2013 y 2014, en un monocultivo de trigo (E1, 32 años) y una rotación de trigo- guisante proteaginoso (E3, 13 años), con dos niveles de fertilización: tradicional y reducida un 50%, bajo laboreo convencional (LC), mínimo (LM) y siembra directa (SD). La nascencia de los cultivos no resultó afectada por el laboreo ni la fertilización, salvo en guisante (LC, 2013). Los rendimientos de trigo fueron siempre mayores en SD, y bajo fertilización reducida en 2014 (E3). Entre las arvenses principales, Chenopodium album, Amaranthus blitoides y Polygonum aviculare, fueron más abundantes en LC o LM. Descurainia sophia y Papaver rhoeas lo fueron en SD y Anacyclus clavatus en LM. La mayor densidad de arvenses se registró en SD y tan solo Lactuca serriola resultó afectada por el nivel de fertilización.This work shows different results obtained in 2013 and 2014 growing seasons in a wheat monoculture field experiment (E1) lasting 32 years, and in a wheat-pea rotation field experiment (E2) lasting 13 years. Two levels of nitrogen fertilization. were considered, traditional and reduced (rates were reduced by 50%), in three different tillage systems: conventional tillage (LC), minimum tillage (LM) and no-tillage (SD). Seedling emergence was not affected by tillage and fertilizer rates except in the pea crop in LC in 2013. Wheat yields peaked in 2014 in SD with reduced fertilization. Considering the weed flora, main species such as Chenopodium album, Amaranthus blitoides and Polygonum aviculare were more abundant in LC and LM. However, Papaver rhoeas and Descurainia sophia were more abundant in SD, and Anacyclus clavatus in LM. The highest weed density was observed in SD and just Lactuca serriola was the only weed species affected by the level of fertilization