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Fluid Journal : Winter 2015
14 The Fluid Journal Winter 2015 This study was conducted during the 2013 growing season to evaluate the placement and application rate of P and K in upland cotton production systems. The trial was implemented at two locations, one at the Tidewater Agricultural Research and Extension Center in Suffolk, VA (TAREC) and the other at the North Carolina department of Agriculture’s Peanut Belt Research Station in Lewiston, NC. Objectives Objectives of this study were to: • Determine the impact on early- season development of upland cotton (Gossypium hirsutum) through first square, nutrient status during the first nine weeks of bloom, and lint yield and quality of placing a fluid P and K fertilizer at multiple depths below the seed during strip-till cultivation • Evaluate selected combinations of The Fluid Journal • Official Journal of the Fluid Fertilizer Foundation • Winter 2015 • Vol. 23, No. 1, Issue #87 Dr. William Hunter Frame and Austin Brown Data indicate 2x2 placement increased early growth in cotton. Summary: At the TAREC location, the 2x2 band of phosphorus (P) and potassium (K) increased early-season plant height compared to standard nutrient management systems. Unfertilized control had the highest P concentrations in cotton petioles throughout the bloom period. The high petiole P concentration may be related to nitrogen (N) deficiency and if this proves to be true then N status will have to be evaluated before making in-season management decisions based on petiole P concentrations. When comparing the 2x2 band and deep placement across multiple application rates, the 2x2 band produced 144 lbs. of lint/acre more than the deep placement of P and K. The 2x2 band containing NPK Sulfur(S) significantly increased early- season vigor of cotton and increased lint yield over the deep placement strategy alone. P and K placed at multiple depths in the strip-till process in combination with 2x2 banding of P and K solutions at planting on crop establishment, growth through first square, nutrient status during the first nine weeks of bloom, and lint yield and quality. Site characteristics Soil type at the TAREC location was an Eunola loamy sand (fine-loamy, siliceous, semi-active, thermic Aquic Hapludults). The soil type at Lewiston was a Rains sandy loam (fine-loamy, siliceous, semi- active, thermic Typic Paleaquults). Soil samples were taken from both locations to a total depth of 12 inches (30cm) and split into depths of 0-3, 3-6, 6-9, and 9-12 inches. Soil test. The Mehlich I soil test levels for each location can be found in Table 1. Fertilizer rates. The base (100%) preplant P and K rates were 40 lbs P2O5/acre and 40 lbs K2O/acre and based on Mehlich I soil test levels. All other agronomic practices were conducted according to Virginia extension recommendations. Experimental Design The study was conducted using four- row plots measuring 12 feet wide by 40 feet long at two locations. Each treatment was replicated four times in a randomized complete block design. The cotton variety grown was Phytogen 499 WRF, a mid-maturing variety with a high yield potential. Thirteen treatments evaluated placement of P and K fluid fertilizers (Table 2). Treatment 1 was an unfertilized P and K control. However, at TAREC, unfertilized plots did not receive N or S, while the unfertilized check at Lewiston received 80 lbs. N per acre in a sidedress application. Two agronomic control treatments were implemented to simulate the current A Look At Placing P and K At Multiple Depths ▼ DOWNLOAD