445-10 Analysis of within-Field Yield Variability in Cotton on Large-Scale Field Tests in North Louisiana.

Poster Number 1329

See more from this Division: SSSA Division: Soil Fertility & Plant Nutrition
See more from this Session: Nitrogen: II
Wednesday, November 5, 2014
Long Beach Convention Center, Exhibit Hall ABC
Share |

Brenda Tubana1, Murilo Martins1, Payton Dupree1, Brandon White1, Marilyn Sebial Dalen1, Saoli Chanda1, Tapasya Babu1, Daniel Forestieri1 and Flavia Bastos Agostinho2, (1)School of Plant, Environmental, and Soil Sciences, Louisiana State University, Baton Rouge, LA
(2)School of Plant, Enviromental, and Soil Sciences, LSU Agricultural Center - Baton Rouge, Baton Rouge, LA
Nowadays, enhanced crop productivity can be partly attributed to wide-scale adoption of site specific management of agricultural inputs through precision farming technology. A demonstration trial adopting a variable rate technology/optical sensing system has been established in six fields in Tensas Parish, LA: A, B, C in 2012 and D, E, and F in 2013. Large strip plots consisted of 12 rows x ~ 300 m-long were established then divided into 10 x 30-m long subplots. The amount of total N applied to each subplot along with lint yield were determined. Deep core samples were collected from five geo-referenced sampling points in each strip plot before planting and after harvest, then divided into 0-15, 15-30, 30-45, 45-60 and >60 cm sections, processed and analyzed for inorganic N content. Using a combine cotton picker and a yield monitor, seed cotton yield for each of the subplots was determined. At planting, the widest range of soil inorganic N within the 0-15 cm depth was recorded in Site B with values from 8 to 62 kg N ha-1 while the lowest range was from 9 to 28 kg N ha-1 for Site F. These observations were in agreement with the variability on the amount of N fertilizer applied to each subplot with standard deviation values of 44 and 6 kg N ha-1 for Site B and Site F, respectively. With lint yield as variable, the highest variability was recorded in Site A (131 kg ha-1) and F (215 kg ha-1) while the lowest variability was observed in Site C (50 kg ha-1) and in Site E (163 kg N ha-1) in 2012 and 2013, respectively. The application of variable N rate based on sensor reading was most profitable in Site A with $32.65 ha-1 followed by Site C with $28.01 ha-1 return.

See more from this Division: SSSA Division: Soil Fertility & Plant Nutrition
See more from this Session: Nitrogen: II