Castor Cake is an excellent fertilizer because of high content of N (6.4%), Phosphoric Acid (2.55%) and Potash (1%) and moisture retention. There is negative correlation between the contents of ricinine in castor seeds and oil content (r = -0.76). This content of ricinine in castor seed is determined by Agro climatic conditions. Nutrient content of Castor Cake: Organic matter - 75 - 80 %, Nitrogen - 4.0 - 4.5 %, Phosphorous - 1.5 %, Potassium - 1.25 - 1.5 %. It also contains some micro nutrients viz., Calcium, Magnesium, Sulphur, Iron, Zinc, Manganese, Copper etc. A typical composition of castor residue/meal is as follows: Nitrogen - 4% min. approx.Phosphourous - 1% min. approx.Potassium - 1% min. approx.Moisture - 10 - 12 % max. approx.Oil Content - 0.7% max. approx. Advantages: 1. It provides all the major & minor nutrients necessary for better plant growth. 2. It also helps in increasing the nutrient uptake by plants . 3. It improves the soil fertility and productivity. 4. It is known to protect the plants from nematodes and termites. 5. It improves the yield & quality of the farm produce. 6. It improves the physical , chemical and biological properties of soil
| 
