ABSTRACT

Lower solubility of P in poultry litter ash (PLA) than conventional P fertilizers such as triple superphosphate (TSP) may reduce P losses in drainage and runoff, however, lower P solubility may reduce its efficacy as a P source. The mineral composition of PLA and acid-induced P release from it were determined. Effects of PLA, TSP or no P fertilization at different initial soil pH values (5, 6 or 7) on the establishment of common bermudagrass (Cynodon dactylon L.) on a representative coastal plain soil (Ruston; fine-loamy, siliceous, semiactive, thermic Typic Paleudults), and P leaching and runoff loss were determined using packed soil columns with incorporated fertilizer (TSP supplemented with K, Ca and Mg to equal that in PLA). Soil columns at near water-holding capacity were seeded, watered daily, and fertilized with N. Yields and tissue concentrations of P, K, Ca and Mg were measured eight and 16 weeks after planting, and total and dissolved reactive P in leachate and in runoff during simulated rainfall were determined. Yields and tissue concentrations were greater where fertilized but there were no consistent differences between PLA and TSP. Leaching of P was negligible for TSP besides PLA due to high P sorption capacity of the soil; however, P runoff losses significantly decreased TSP > PLA > control. Given no disadvantage of PLA compared to TSP on bermudagrass establishment but evidence for reduced loss in runoff, tentative results should be confirmed using field plots.

摘要

与常规磷肥（如三重过磷酸钙（TSP））相比，磷在家禽凋落灰（PLA）中的溶解度较低，可以减少磷在排水和径流中的损失，但是，较低的磷溶解度可能会降低其作为磷源的功效。确定了PLA的矿物成分和酸诱导的P释放。不同初始土壤pH值（5、6或7）下PLA，TSP或无磷施肥对普通百慕大草（Cynodon dactylon）建立的影响L.）在代表性的沿海平原土壤（Ruston;细壤土，硅质，半活性，热典型Tyale Paleudults）上，使用装有肥料（TSP补充了K，Ca和Mg的肥料）的填充土壤柱测定了P的淋失和径流损失等于PLA中的值）。播种，持水量接近土壤的土壤柱，每天浇水，并施以氮肥。在种植后八周和十六周分别测量磷，钾，钙和镁的产量和组织浓度，并分析渗滤液中和渗滤液中总的和溶解的反应性磷。确定了模拟降雨期间的径流。受精后产量和组织浓度更高，但PLA和TSP之间没有一致的差异。由于土壤对磷的高吸附能力，除PLA外，TSP对磷的淋溶作用可忽略不计。但是，P径流损失大大降低了TSP> PLA>控制。考虑到在百慕大草种植上PLA与TSP相比没有缺点，但有径流损失减少的证据，因此应使用田间图确认试验结果。