Response of Wheat and Barley Varieties to Phosphorus Fertilizer, 2011

Abstract

Phosphorus fertilizer represents a significant portion of the cost of producing small grains. Some evidence exists that there are differences in the ability of small grain varieties to take phosphorus up from the soil and utilize this nutrient in the grain. The objective of this study is to determine if barley and wheat varieties grown in Arizona differ in their response to phosphorus fertilizer. A study was conducted for the third year at the Maricopa Agricultural Center testing the response of 7 barley and 14 wheat (12 durum wheat and 2 bread wheat) varieties to 2 phosphorus rates (0 and 100 lbs P₂O₅/acre). Averaged over varieties, the grain yield increase due to phosphorus application of 100 lbs P₂O₅/acre was 346 lbs/acre for barley and 516 lbs/acre for wheat, similar to previous years. Despite the wide range of apparent yield response (0 to over 1000 lbs/acre) of the varieties to P fertilizer, these differences were not statistically significant. Furthermore, there was no consistency in the yield response of the varieties between this year and last year. Some of the varieties that responded greatest to P fertilizer last year, responded least this year, and vice versa. Therefore, there appears to be no differences in the response of barley and wheat varieties typically grown in Arizona to phosphorus fertilizer.