potassium fertilizer recommendations through determination of mitscherlich-bray equation coefficients for irrigated wheat

Determination of the Nonlinear Equation Coefficients for Flow through Coarse Alluvium Foundations

As a result of the limitations in the application of Darcy Law (V=ki) to linear-laminar flow regimes through porous media and due to the fact that in coarse alluviums, the Reynolds number may exceed its critical value, the so-called Laplas equation cannot be used for precise analyses of coarse granular foundations. A more general relationship is, therefore, required for such cases. However, a c...

Crop Potassium Nutrition – Implications for Fertilizer Recommendations

Determination of the Nonlinear Equation Coefficients for Flow through Coarse Alluvium Foundations

As a result of the limitations in the application of Darcy Law (V=ki) to linear-laminar flow regimes through porous media and due to the fact that in coarse alluviums, the Reynolds number may exceed its critical value, the so-called Laplas equation cannot be used for precise analyses of coarse granular foundations. A more general relationship is, therefore, required for such cases. However, a c...

Revision of Potassium Soil-test Interpretations and Fertilizer Recommendations

There is a long history of potassium (K) fertilization research in the North-Central Region. Sustained Iowa field research efforts have focused on developing soil-test K (STK) interpretation and studying the effect of K fertilization strategies on grain yield and STK. Because of changes in the soil-test K method used in Iowa, information published over time should be evaluated separately. Publi...

The Phosphorus and Potassium Fertilizer Value of Two Poultry Litter Sources Used for Flood-Irrigated Rice

Few studies have examined the use of poultry litter as an alternative to inorganic P and K fertilizers for flood-irrigated rice. The objective of this study was to compare fresh and pelletized poultry litter to inorganic P and K fertilizers to document the availability of P and K in poultry litter. Inorganic P and K fertilizers, fresh broiler litter, and pelletized litter were preplant-incorpor...

Combining Field and Simulation Studies to Improve Fertilizer Recommendations for Irrigated Rice in Burkina Faso

estimated at 4.0 to 4.5 t ha 1 (Illy, 1997; Wopereis et al., 1999), and in general two crops per year are grown. Development of improved fertilizer recommendations entirely based This compares to average yields in the Sahelian and on field experiments is time-consuming and costly. We employed a comSavannah regions of 3.0 to 5.5 t ha 1. The cropping bination of two simulation models and selected...