Evaluation of Calcium Soil Conditioners in an Irrigated Cotton Production System, 1997

Abstract

A single field experiment was conducted at Paloma Ranch, west of Gila Bend in Maricopa County Arizona in 1996 and 1997. NuCotn™ 33B was dry planted and watered -up on 15 April and 1 April in 1996 and 1997. Various rates and times of application of nitrogen (N) and calcium (Ca) from two sources [N-Cal™ (CO(NH₂)₂•CaC1₂) and CAN-17 (CaNO₃)] as well as a standard N source, UAN-32 [NH₄NO₃•CO(NH₂)₂] were used to evaluate the check In 1996 treatments 1, 2,and 3 each received a total of 280 lbs. N/acre, treatment 4 received a total of 210 lbs. N/acre, while treatment 5 received a total of 301 lbs. N/acre. Treatment 1 received only farm standard applications of UAN-32. Treatments 2 and 4 each received a total of 72 lbs. of Ca/acre. Treatment 5 received a total of 79 lbs. Ca/acre from N-Cal™ while treatment 3 received a total of 301 lbs. Ca/acre from CAN -17. Treatment 4 used a conservative N approach (UA guidelines). 1997 was similar to 1996 in the general nature of the experimental design, but different in its actual treatments. Treatments 2, 3, 4, and 5 each used N-Cal™ for the first two irrigation applications then UAN -32 for continued crop N needs. Treatment 4 used a conservative N approach (U A guidelines). Treatments 3 and 5 each received two foliar applications of N-Cal™ Foliar applications consisted of N-Cal™ mixed with urea for a 15-0-0-8 formula and applied on 22 July and 29 July via a high cycle applicator at a 5 gal/acre rate of N-Cal™ (carrier rate = 40 gal /acre). No significant differences were found among the various treatments in terms of plant growth, soil water content, ECₑ values, and sodium absorption ratios in 1996 or 1997. Lint yields were not significantly different in 1996 (P < 0.05) or 1997 (P < 0.05).