PHOSPHORUS AVAILABILITY WITH ALKALINE/CALCAREOUS SOIL

摘要: Phosphorus (P) is an essential nutrient required by plants for normal growth and development. The availability of P to uptake utilization impaired in alkaline calcareous soil due the formation poorly soluble calcium phosphate minerals. Adding fertilizer at “normal” rates with conventional methods may not result optimal yield crop quality these soils common arid semi-arid regions. Several management strategies have been found improve nutrition grown soil. Research results show that relatively high are crops soil, increasing needed as lime content increases. Concentrated bands solubility resulting increases, even when applied test concentrations. Applying organically complexed form biosolids or a mixture liquid humic substances can also enhance Application slow release cation complexing specialty materials has shown effectively increase yields In-season through irrigation water deliver plant roots deficiencies observed, but effectiveness less than incorporated into Finally, it important maintain proper balance other nutrients general health avoid excess induced nutrients. In some cases, new need further refinement regard rates, timing, technique; all potential improving supply PHOSPHORUS NUTRITION macronutrient, being large quantities (~0.2 0.8%) (Mengel Kirkby, 1987; Mills Jones, 1996). Potassium nitrogen only mineral larger P. Providing adequate be difficult, especially Alkaline defined pH greater neutral, typically 7.5 8.5. Calcareous having presence significant free (calcium magnesium carbonate). Lime dissolves neutral acid does readily dissolve and, instead, serves sink surface adsorbed precipitation. bioavailability strongly tied pH. iron aluminum minerals reduced acidic approaches nearly neutral. This maximum 6.5 declines again increases range. effect driven reaction calcium, lowest about 8.