Contents: 1. Agricultural economics. 2. Agricultural meteorology. 3. Agricultural physics. 4. Agronomy. 5. Crop protection. 6. Analyses and interpretation. 7. Irrigation and water management. 8. Physiology and biochemistry. 9. Soil chemistry and fertility. 10. Soil and watershed engineering. 11. Statistics. This book aims to be a basic and fundamental book for the students and researchers in numerical solving. The book has been designed in a very simple language. Formulas have been presented in the most fundamental and basic calculations. The book has been divided into several chapters and broadly reflects the need of such subject selection as most of the calculations in agriculture pertains to those areas. This proceeds with the most basic and fundamental conversions and formulas required for computing a calculation. Most of the units, dimensions and relevant symbols have been noted in the form of their actual notations.