Effects of SHALLOW VS. DEEP INSEMINATION AND SEMEN DOSE ON TURKEY FERTILITY

resulted in highest leaf N content. Only one-half the amount of controlled release N was used on plants in the combination treatment as was used on plants where controlled release N was the only fertilization. Soil tests did not show significant variation between treatments with regard to pH, salinity, P, K, Ca and Mg content. The pH ranged from 6.5 to 7.4 and the salinity was not high enough to adversely influence plant growth. Temperature and microbial activity have been reported to influence the release of nitrogen from granules of sulfurcoated urea. The plants in this experiment were subjected to normal outdoor fluctuation in temperature which may account for some of the variation noted. The length of the experiment probably was too short for a change in pH to be reflected as the sulfur was converted to sulfates. Even had this happened, the change would have been slight because a very small amount of sulfur was applied-6 to 12 grams per cubic ft of soil mix. The reason for dilute applications of fertilizer at each irrigation (constant fertilization treatment) was to supply nitrogen as required. The procedure is based on the assumption that water use (evapotranspiration) and plant growth are closely correlated. While it is evident that the correlation is close enough for practical use, it is also evident that difficulties can arise from complete reliance on the procedure. The fluctuation in leaf N suggests that it may be below optimum levels at times. Also, changes in rate of evapotranspiration may not always be correlated with plant growth. Such environmental conditions as dry wind may increase evapotranspiration, without a corresponding increase in growth. Repeated applications of dilute fertilizer solution (under such conditions) may result in an injurious buildup of salt levels. A combination of controlled release and constant fertilization overcame the difficulties of each treatment used separately, and resulted in greatest uniformity of N content. This was reflected in the uniform growth of the test plants. Eflects oj