|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|152419||2017||14 صفحه PDF||سفارش دهید||9392 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Field Crops Research, Volume 213, November 2017, Pages 51-64
The use of controlled release fertilisers (CRF) is being promoted in the Australian sugarcane industry to improve nitrogen (N) use efficiency and reduce N losses through better matching of N release with crop N demand. Little is known, however, about the required synchrony due to limited information on both N uptake patterns of sugarcane and N release patterns from CRF under different crop growing conditions. This paper uses APSIM scenario modelling to characterise N uptake patterns of sugarcane plant and ratoon crops in response to seasonal variability and different climatic and management conditions (e.g. level of water and N input, time of planting/ratooning) at five sites within the Australian sugarcane growing region. The results showed considerable variations in crop N uptake patterns across seasons, sites and under different management scenarios. However, for a given site, crop N uptake patterns during the early crop growth stage varied little between seasons (<0.5Â gÂ N/m2). All the simulated N uptake patterns showed an initial lag period with little N uptake (average <1.7Â g/m2), followed by a relatively sudden transition to a rapid and linear uptake period with the rate and duration of the linear phase depending on management, climatic and soil conditions. Over the course of the season the variation in total N uptake increased especially when the sugarcane system had a limited irrigation allocation or was rainfed. These N uptake patterns could be used to inform the design and management of CRF to optimise synchronisation with sugarcane crop N demand. The predicted average lag periods ranged from 55Â days to 137Â days. The average lag period was shorter for the ratoon crops (55â83Â days) as compared to that for the plant crops (79â137Â days) and shorter for later planted or ratooned crops that experienced warmer temperatures in the first months. Temperature also contributed to a location effect, which was particularly strong for plant crops where, for example, the average lag period for early plant crops ranged from 102Â days for the most northern tropical site to 137Â days for the most southern subtropical site. These differences need to be considered in the design of CRF release patterns and management of timing of application. The predicted average maximum linear N uptake rate ranged from 0.25 to 0.38Â gÂ N/m2/day and driven by direct and indirect effects of solar radiation input. The greater variations in the final total N uptake amount present uncertainty on how much CRF needs to be applied ahead of different seasons. Better seasonal climate forecasting may enable a more precise estimation of total season N requirement by the crop and the amount of CRF required.