Nitrate leaching and residual effect in dairy crop rotations with grass–clover leys as influenced by sward age, grazing, cutting and fertilizer regimes

摘要: Abstract Intensive dairy farming, with grass-arable crop rotations is challenged by low N use efficiency that may have adverse environmental consequences. We investigated nitrate leaching and fertility effects of grass–clover leys for five years in two organic different grassland proportions (33 67%) managements terms cutting, grazing, fertilization combinations thereof. In grass–clover, the combination grazing caused excessive (average 60 kg N ha −1 ) but leaving out either or full-time substantially reduced losses to on average 23 kg . There was no linear relationship between sward age leaching. The annual surplus grasslands only weakly related ( R 2  = 0.05, P consisting barley wholecrop undersown Italian ryegrass, (2) medium–low (10–20 kg 1-yr-old grasslands, (3) medium (25–50 kg barley–pea 2-4-yr-old 2-yr-old most (36–46 kg ), (4) high (>50 kg lupin maize, where especially maize consistently all 81 kg ). Great care should be taken during phases rotation cause considerable build-up fertility. With due best management practice, levels.