EFFECT OF WINTER CEREAL SOWING TIME ON YIELD AND NITRATE LEACHING BASED ON EXPERIMENTS AND MODELLING

TY - ABST

T1 - EFFECT OF WINTER CEREAL SOWING TIME ON YIELD AND NITRATE LEACHING BASED ON EXPERIMENTS AND MODELLING

AU - Cronin, Iris Vogeler

AU - Thomsen, Ingrid Kaag

AU - Hansen, Elly Møller

PY - 2020

Y1 - 2020

N2 - The sustainable management of intensively managed agricultural land requires high productivity with low environmental impacts. There is a lack of understanding if early sowing of winter cereals is a potential mitigation measure for reducing nitrate leaching losses. To test this, an experiment was conducted in Denmark over three years (2016-2019) with timely and ca. three weeks earlier sowing of winter rye and with different levels of nitrogen (N) fertilisation. Early sowing reduced nitrate leaching but did not affect grain yield or grain N concentration. Deterministic models are increasingly being used to aid farm management and inform policy making and compliance. The Agricultural Production Systems sIMulator (APSIM) modelling framework has been widely used worldwide to simulate crop growth and N uptake, and estimate environmental impacts. The model has, however not been used under Danish conditions. The APSIM model was evaluated and calibrated for winter rye, and the climatic conditions prevailing in Denmark. After changing a few crop coefficients and variables, the model adequately simulated dry matter yield and grain N concentration across the different N fertilisation rates. Comparison between measured and predicted nitrate leaching showed poor performance for the timely sown winter rye, whereas the prediction was better for the early sown winter rye. Cumulative nitrate leaching over the three years studied also shows better performance of the model. Long term simulations suggest a slight reduction in nitrate leaching, on average of 5%, with the use of early sowing.

AB - The sustainable management of intensively managed agricultural land requires high productivity with low environmental impacts. There is a lack of understanding if early sowing of winter cereals is a potential mitigation measure for reducing nitrate leaching losses. To test this, an experiment was conducted in Denmark over three years (2016-2019) with timely and ca. three weeks earlier sowing of winter rye and with different levels of nitrogen (N) fertilisation. Early sowing reduced nitrate leaching but did not affect grain yield or grain N concentration. Deterministic models are increasingly being used to aid farm management and inform policy making and compliance. The Agricultural Production Systems sIMulator (APSIM) modelling framework has been widely used worldwide to simulate crop growth and N uptake, and estimate environmental impacts. The model has, however not been used under Danish conditions. The APSIM model was evaluated and calibrated for winter rye, and the climatic conditions prevailing in Denmark. After changing a few crop coefficients and variables, the model adequately simulated dry matter yield and grain N concentration across the different N fertilisation rates. Comparison between measured and predicted nitrate leaching showed poor performance for the timely sown winter rye, whereas the prediction was better for the early sown winter rye. Cumulative nitrate leaching over the three years studied also shows better performance of the model. Long term simulations suggest a slight reduction in nitrate leaching, on average of 5%, with the use of early sowing.

KW - Nitrate leaching, increasing N fertilisation rates, early and timely sowing, winter rye, APSIM

M3 - Conference abstract for conference

T2 - 16th ESA Congress

Y2 - 1 September 2020 through 4 September 2020

ER -