Integrated Effect of Azolla in Combination with Graded Doses of Nitrogen on Growth and Agronomic Parameters of Rice Crop

摘要

Azolla pinnata, a floating water fern, is used as green manure (bio-fertilizer) for increasing rice yields. It can fix di-nitrogen in association with Anabaena Azollae therefore it helps to reduce the recommended dose of chemical-nitrogen when Azollais applied to the paddy fields. Azolla was grown in pots and trays in February, 2016 under laboratory and fieldby making trenches (2m x 2m x 0.2m) in March, 2016. A field experiment was conducted at CSKHPKV, Palampur to study and evaluate the effects ofAzolla alone and in combination with graded doses of nitrogen in rice crop. The rice variety used was HPR-2143. The results of the experiment revealed thatthe maximum plant height was recorded in 50 kg N ha~(-1) + 8 t Azolla, maximum number of tillers m-2in 125 kg N ha~(-1) + 8 t Azolla, maximum effective tillers m~(-2) in 100 kg N ha~(-1) + 8 t Azolla. The highest number of grains per panicle was recorded in 125 kg N ha~(-1) +4 t Azolla. The application of 125 kg N ha~(-1) + 8 t Azolla resulted in thehighest grain and straw yield. It can be concluded from the experiment that integrated use of Azolla and nitrogen fertilizers is an effective way for increasing rice yield.