滴灌精准施肥装置棉田施氮配肥能力研究

在SPAD营养诊断氮素施肥模型基础上,确定滴灌棉花不同生育期的最佳施氮量;结合单次灌溉时间、轮灌区面积的相关研究,确定不同规格配肥盘的配肥时间。通过对比配肥盘单位时间配肥量与施肥量之间的关系,确定滴灌精准施肥装置的施氮配肥能力。结果表明:滴灌棉田单位时间施肥量只与单井出水量Q和特定棉花生育时期的施氮量Nd有关。该装置100、200、300 g 3个规格配肥盘无论在任何单井出水量情况下,都无法满足棉花全生育期追施氮肥的需要,400 g与500 g规格的配肥盘也只能满足特定单井出水量条件下的棉花追氮任务,并在此基础上对装置的优化与改进进行了阐述。

Distribution and Application of Urea with Precision Fertilization Device of Drip Irrigation in Cotton Fields

On the basis of SPAD model for nutrition diagnosis of nitrogen fertilization, we determined the optimal nitrogen rate at the different growth stages of cotton with drip irrigation under mulch. Combining with relevant research at a single irrigation time and acreage of round irrigated area, we definited the fertilizer time of different specifications fertilizer disc. The capacity of the device with combined application of nitrogen fertilizer was determined by comparing with distribution and application of combined fertilizer at unit time. The results showed that the rate of fertilization per unit time for the device was related to water yield from any single well and nitrogen fertilizer in the whole cotton growth period, and the device were unable to meet the needs of topdressing when it used fertilizer disc of sizes with 100g, 200g and 300g. Furthermore, fertilizer disc of sizes with 400g and 500g could only meet topdressing nitrogen level of cotton under condition of the specific water yield from a single well. And according to our research described above, we explored the approach to optimize and improve device.