|
|
Feasibility of variable rate application of Diammonium Phosphate fertilizer to wheat crop under center pivot irrigation system.
|
|
|
Abstract: A study was conducted, on a 30 ha wheat field under a solar energy powered center pivot irrigation system in a commercial farm located 400 km north of Khartoum, Sudan, to evaluate the feasibility of variable rate fertilizer application of Diammonium Phosphate (DAP) on wheat crop based on variable soil phosphorus content. Soil phosphorus content was divided into three categories (low: 3.75 to .50 ppm, medium: 4.51 to 5.25 ppm and high: 5.26 to 6.00 ppm) and a GIS soil phosphorus content map of the experimental field was generated. Three variable application rates (200 kg ha_1, 160 kg ha_1 and 120 kg ha_1) of granular DAP fertilizer were determined to fit the low, medium and high soil phosphorus contents, respectively. The the DAP fertilizer rate of 200 kg ha_1 was the rate practiced for wheat production in the experimental farm. The normalized Difference Vegetation Index (NDVI), measured at different wheat growth stages using sentinel-2 satellite images, and wheat grain yield were used to evaluate the response of wheat crop to the variable DAP fertilizer application rates. Excluding the tillering stage, the results showed significant differences in the NDVI values among different soil phosphorus levels and DAP fertilizer application rates at other growth stages, including stem elongation, grain filling and maturity stages. Moreover, wheat yield results showed significant differences among different soil phosphorus contents (P > F = 0.0001) and DAP fertilizer application rates (P > F = 0.0457). On the average, the highest yield of 2.449 t ha_1 was recorded in the field areas treated with the high DAP fertilizer application rate (200 kg ha_1), where the second highest yield of 2.441 t ha_1 was observed in field areas under the medium DAP fertilizer application rate (160 kg ha_1); however, no significant differences between these two yield values. Based on these results, the total savings of the DAP fertilizer was estimated to be 792 kg (equivalent to 475.2 $) in the experimental field (30 ha), only when the medium DAP fertilizer rate (160 kg ha_1) was used in the medium and high soil phosphorus zones, saving 15.84 $ ha_1 without affecting production.
|
| Publication year |
2022
|
| Organization Name |
|
| serial title |
Journal of King Saud University – Scienc
|
| Author(s) from ARC |
|
| External authors (outside ARC) |
|
| Publication Type |
Journal
|