152 results about "Water stress" patented technology

The invention discloses a method for remote sensing estimation of net primary productivity of plants. The method comprises the steps of performing data pre-processing on remote sensing data; extracting LAI data of an MODIS product in the remote sensing data, and calculating an FPAR; calculating astronomical radiation total Q0 according to geographical location information of a research area including longitude and latitude and date; extracting an empirical coefficient according to conventional global radiation and sunshine percentage data of the research area; using Q0 and the empirical coefficient to calculate solar total radiation quantity SOL; calculating photosynthetically active radiation (APAR) according to the FPAR and the SOL; extracting soil water content and an empirical parameter in the remote sensing data, calculating current leaf water potential, and calculating water stress factor in combination with the previous empirical coefficient; extracting temperature data in the research area in meteorological data, calculating temperature stress factor f1(Ta); calculating solar energy utilization rate epsilon according to f1(Ta), and the maximum solar energy utilization rate; and calculating net primary productivity (NPP) according to the APAR and epsilon. The method has the advantages of being high in estimation precision.

The invention relates to a substrate salt content automatically adjusting soilless vegetable planting method. The method comprises collecting substrate water content data at a fixed time interval; determining whether substrate water content is lower than a water stress critical value, if so, performing irrigation through nutrient solution; estimating substrate salt content; determining whether the substrate salt content is higher than a salt damage critical value, if so, performing rinsing through the nutrient solution; repeating the above steps until the growing period ends. Meanwhile, the invention provides a substrate salt content automatically adjusting soilless vegetable planting system applying the method. The substrate salt content automatically adjusting soilless vegetable planting method and system achieves automatic adjustment of soilless planting substrate salt content, saves human resource costs and fund costs, ensures fine water and fertilizer supply of soilless planted crops, avoids salt damage to the crops, and meanwhile, reduces waste of the nutrient solution, maximizes the utilization rate of the nutrient solution and provides technical guarantee for high-quality and high-efficiency yield of the soilless planted crops.