{"id":965,"date":"2017-09-22T14:22:14","date_gmt":"2017-09-22T19:22:14","guid":{"rendered":"https:\/\/agrilife.org\/mid-coast-ipm\/?p=965"},"modified":"2019-05-09T11:43:11","modified_gmt":"2019-05-09T16:43:11","slug":"testing-for-residual-soil-nitrogen-cotton","status":"publish","type":"post","link":"https:\/\/agrilife.org\/mid-coast-ipm\/testing-for-residual-soil-nitrogen-cotton\/","title":{"rendered":"Testing for Residual Soil N can Save $ – Cotton"},"content":{"rendered":"

\"\"<\/a>Two trials were conducted in 2017 the objective to evaluate the effect of reducing by the amount of residual nitrogen found in soil tests at depths up to 24 inches. Each of these trials were conducted with large plots in grower fields. What follows is the research report for the Cotton test<\/strong>. (printable version<\/a>)<\/p>\n

Evaluation of Reducing Nitrogen Fertilizer Application by Residual Soil <\/strong>Nitrogen Found to Depths of 24 Inches in Cotton<\/strong><\/p>\n

Investigator: Stephen Biles\u00a0and Geri Kline<\/p>\n

Cooperator: Shane May\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/strong><\/p>\n

Summary<\/u><\/strong><\/p>\n

A field research trial was conducted to evaluate the effect of using soil sampling to twenty-four inches to reduce nitrogen fertilizer application. Nitrogen fertilizer was applied to treatments of 68, 34, and 0 lbs N per acre in a replicated field trial. Lint yield of the treatments was not statistically significant between the three nitrogen fertilizer levels. Thought not statistically significant, the middle N rage provided a numerical advantage of $22.08 and $25.98 in increased profits over the 0 and 68 lbs N treatment, respectively.<\/p>\n

Objective<\/u><\/strong><\/p>\n

Research conducted over the past decade has demonstrated nitrogen fertilizer applications can be reduced by the amount of residual nitrogen found in soil tests at depths up to 24 inches. This research was conducted to evaluate this concept on large scale plots in a grower field.<\/p>\n

Materials and Methods<\/u><\/strong><\/p>\n

A field was sampled for soil nutrients in early January using a hydraulic soil probe to 24 inches. Soil testing was conducted at the Texas A&M Soil, Water, and Forage Testing Laboratory in College Station Texas. Results of the soil testing found 32 lbs N at 0-6 inches and 72 lbs N (11.95 ppm) from 6-24 inches for a total of 104 lbs residual N per acre (Table 1).<\/p>\n

\"\"<\/a><\/p>\n

Pre-plant nitrogen fertilizer treatments were applied by field sprayer at the treatment rates of 0, 34, and 68 lbs\/A on February 6, 2017. The fertility treatments were determined as follows:<\/p>\n