Azolla pinnata, a floating water fern, is used as green manure (bio-fertilizer) for increasing rice yields. It can fix di-nitrogen (N2) in association with Anabaena Azolla therefore helps to reduce the recommended dose of chemical-nitrogen when Azolla is applied to the paddy field. The species of Azolla has been collected from different parts of the country and maintained in the Soil Science Division, NARI, Khumaltar, Lalitpur. A field experiment was conducted at the Agronomy farm, Khumaltar to study and evaluate the effects of Azolla pinnata compared to other nutrient sources to the rice during 2015/16 and 2016/2017. The experimental design was a randomized complete block design (RCBD) comprising of 6 treatments and 3 replications. The rice variety used was Khumal-4. The results of the experiment revealed that incorporation of Azolla to rice field in combination with the recommended dose of Phosphorous and Potassium gave comparable yields to that of the recommended dose of Nitrogen, Phosphorous, and Potassium. Also, yields were comparable to that of the use of compost (10 ton/ha). The study indicates that Azolla could be a very good alternative supplementary source of fertilizer-N for rice production.

An experiment was conducted in factorial design with three replications in Nawalpur, Sarlahi, Nepal in 2018 and 2019 to investigate the impact of calcium and phosphorous application on yield and yield components of groundnut (Arachis hypogaea L.). Baidehi variety of groundnut was used. Calcium concentrations in three levels (0, 110, and 165 kg ha-1 from Gypsum) and phosphorous rates in three levels (0, 25, and 50 kg ha-1 from SSP) were used in this study. The application of calcium had a major impact on pod production, quantity of filled pods, and hundred seed weight, with 165 kg ha-1 calcium from gypsum performing significantly better than the others. The highest pod yield (2006 and 2477 kg ha-1) was obtained from calcium 165 kg ha-1 in 2018 and 2019 respectively. Calcium application (165 kg ha-1) increased the mean pod yield by 24% compared to the control. Control plots resulted in more than 13% empty pods (pops) compared to when applied with 165 kg Ca ha-1. Phosphorus was rich in the inherent soil leading to no significant effect on the yield components. According to the findings of this research, efficient fertilizer application, especially calcium and phosphorus, is critical for groundnut nutrition and pod filling.