Abstract:
Spatial patterns in gypsum requirement of a salt affected field at Shahdau village in Dera Ismail Khan district were determined before and after treatment with gypsum. Surface soil samples (0-25 cm) were collected from six parallel transacts at 15 m intervals. Gypsum requirement was determined for all these samples. Each transect was divided into two strips. One strip received a single uniform rate of gypsum while the adjacent strip was treated with variable rates of gypsum to match gypsum requirement of different locations. Wheat crop was planted in the whole field after gypsum application. At harvest, wheat yields were measured at 15 m intervals from an area of 1 m2 in both the strips from all the six transacts. Surface soil samples (0-25 cm) were also collected from both the strips from all the six transacts. GR was determined for all these samples. The data on GR and wheat yields were subjected to classical statistical analysis and geostatistical technique of semivariogram analysis. Results showed that there was a considerable variation (CV = 63%) in GR before and after gypsum application (Cv = 75 and 106 %). GR was significantly reduced with gypsum application. There were strong spatial patterns in GR before and after treatment in variable-rate strips. Similarly there was a considerable variation in grain yields (CV = 50 and 47%) with strong spatial patterns.
Aman Ullah Bhatti , Ahmad Bakhsh and Akbar Hussain Gurmani , 2000. Spatial Patterns in Gypsum Requirement Before and After Gypsum Application . Pakistan Journal of Biological Sciences, 3: 1580-1582.
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