Nitrogen, Phosphorus, and Potassium Nutrition of the Edaphic Ecotypes in Cynodon dactylon (L.) Pers.

A differential response to nitrogen, phosphorus, and potassiumwas observed for the three edaphic ecotypes in Cynodon dactylon(L.) Pers. naturally occurring at Malla, Shiwalik, and Chandigarh.The soils of these sites differ markedly with respect to availablenutrients. The better growth of the Malla population comparedto the Chandigarh population in low potassium and low nitrogenmedia could be related to the low availability of these nutrientsin the calcareous Malla soil. The Shiwalik population tendedto show an intermediate behaviour. Whilst the Malla populationwas susceptible to ‘phosphate toxicity’, the growthyield of the Shiwalik and the Chandigarh populations improvedwith increase in phosphorus in the medium. The three populationsalso differed from each other with respect to the uptake ofvarious nutrients. These results could be correlated with thenatural habitat conditions in which the three ecotypes occur.It was concluded that besides calcium which was shown to bepartly responsible for the restriction of the three ecotypesto their respective habitats, the availability of nitrogen,potassium, and also phosphorus may play an important role.