Abstract
Agriculture developed about 10,000 years ago in the Fertile Crescent of Iran and Palestine. Rice cultiva tion also began in central China near the Yangtze River over 8500 years ago. These early farmers used a natural biological system to fertilize the rice; they used Azolla's ability to draw down nitrogen from the atmosphere, which then bio-fertilized the growing rice plants. The use of Azolla in rice production use dates back at least a thousand years in Vietnam. Some legends say that its cultivation was introduced by the Buddhist Monk Khong Mirh Khong in the eleventh century. Azolla /mosquito fern/ duckweed fern/ fairy moss/ water fern is a free-floating aquatic fern and is genus which belongs to family Salviniaceae. It grows in fresh water and is naturally available mostly on moist soils, ditches marshy ponds and is widely distributed in tropical belts of India. Shape of Indian species is typically triangular measuring about 1.5 to 3.0 cm in length 1 to 2 cm in breadth. Roots emanating from growing branches remained suspended in water.
The dorsal lobe which remains exposed to air is having a specific cavity containing its symbiotic partner, a Blue Green Algae (BGA), the Anabaena azollae. The fern is capable of fixing atmospheric nitrogen in the soil in the form of NH4+ and becomes available as a soluble nitrogen for the cultured species. A pot experiment was conducted in the experimental field of the University of Ghana, Legon to observe the effectiveness of dry Azolla as N source in flooded rice field. The treatments consist of incorporating fresh Azolla (FA at 90 kg N/ha), dry Azolla (DA at 90 kg N/ha), dry Azolla + Ammonium sulphate (DA at 45 kg N/ha + AS at 45 kg N/ha), fresh Azolla + dry Azolla (FA at 45 kg N/ha + DA at 45 kg N/ha), ammoni um sulphate (AS at 90 kg N/ha) and a control (C at 0 kgN/ha). The treatments were applied 8 days after transplanting rice. Results showed that the DA + AS treatment, that is, the treatment where dry Azolla + ammonium sulphate were used to fertilize the rice had the highest dry weight and total N yield followed by the treatment AS. Total N for the DA + AS treatment was 36.67% over the control whilst that for the AS was 25% over the control.
This experiment results stated that the Azolla is potential for the nitrogen fixation in the soil. There is ample scope for improving the productivity of livestock by better balancing of nutrients and optimizing the utilization of feed resources. Azolla has been reported as potential feed supplement for dairy animals, which have rich nutrient and mineral profile. An On Farm Trail was conducted to study the effect of Azolla as feed supplement in buffaloes. The control group (C) farmers practice was fed wheat straw and green fodder with cottonseed cake. In the treatment group (T) 1.5 kg fresh azolla/animal/day was supplemented over conventional ration. This experiment was stated that the dry Azolla is useful for cattle feed and the milk yield is gradually increased. An attempt was made to evaluate the proximate value of Azolla pinnata as a feed for poultry. Azolla was cultivated following the NARDEP method. After harvesting it was sundried and stored in polyethylene bags and was further analysed for proximate principles. The dry matter content was 90.03 %, 22.79 % crude protein, 3.59 % ether extract, 15.49 % crude fibre, 19.46% total ash, 38.67 % NFE, 1.93% calcium and 0.26% phosphorus, this article results explains the suitability of Azolla as a poultry feed. To evaluate the nutritive value and digestibility of Azolla in ruminants by in vitro techniques. The crude protein, crude fibre and ether extract contents were at a level of 21.37%, 12.5% and 2.3%, re spectively. The neutral and acid detergent fibre levels were about 35.4 and 23.9%, respectively. The average in vitro dry matter digestibility, in vitro organic matter digestibility and metabolozable energy contents were 79.5%, 63.8 mg/200mg and 7.36 MJ/kg DM (1759 kcal/kg), respectively. The various protein fractions A, B1, B2, B3 and C estimated by Cornell net crude protein solubility system were 18.22, 42.56, 15.15, 7.47 and 16.61% of total protein, respectively. The Azolla contained significantly higher B1 fraction followed by A, B2 and C and lowest fraction of C. Thus in view of above, present study indicated Azolla to be a good source protein supplement with 21.37% crude protein with highest B protein fractions, moderate source of energy (1759 kcal ME/kg), high dry matter and organic matter digestibility and rich in trace minerals thus could be used as an alternate protein supplement or as supplementary protein supplement to ruminants.
Present investigation was carried out to study the influence of fresh Azolla when used as basal incorpo ration in soil and as dual cropped with rice variety Mahsoori separately and together with and without chemical nitrogen fertilizer in pots kept under net house conditions. Results showed that use of Azolla as basal or dual or basal plus dual influenced the rice crop positively where use of fern as basal plus dual was superior and served the nitrogen requirement of rice. There was marked increase in plant height, number of effective tillers, dry mass and nitrogen content of rice plants with the use of Azolla and N-fertilizers alone and other combinations. The use of Azolla also increased organic matter and potassium contents of the soil. The overall study explains about the Azolla is suitable for the alternative protein supplement feed for the cattle's, pigs, poultry etc... and the Azolla useful for the organic fertilizer to fix the nitrogen along with the anabaena
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