Impacts of Agriculture Practices on Sustainable Biodiversity in Rajshahi District

Abstract

Bangladesh is one of the biodiversity rich countries in the world. However, the biodiversity is declining day by day due to anthropogenic activity like human population growth, habitat destruction, pollutions, agriculture, global warming, forest fragmentation etc. Agricultural activities such as tillage, drainage, intercropping, rotation, grazing and extensive usage of pesticides and fertilizers have significant implications for wild species of flora and fauna. Some management techniques, changes in agricultural practices, monocropping, hybridization and land degradation, create such fundamental habit changes that there are significant shift in species composition. The study was conducted to determine the impacts of agriculture practices on sustainable biodiversity in Puthia Upazilla, Rajshahi district. There are number of undesirable environmental impacts associated with natural vegetation and trees, indigenous plant diversity, exotic plant, organic matter, fish diversity, shortage of water, wild life and indigenous bird species diversity, hybrid crops, use of chemical fertilizer, pesticides herbicide, insecticide found in the study area. It was found that, some agricultural practices with the use of modern technologies causes a depletion of biodiversity. There are about 15052 hectre of cultivable land present in Puthia. In 1990s, about 60.2% of people used traditional method of cultivation. On the other hand, now a days about 75% of peoples are using modern methods of cultivation. In 1990, cultivable land area were 36157 acre of which only 12.5% were irrigated but in 2014, cultivale land were 36481 and 100% were under irrigation. About 5-10% tubewell water are available In March-May and 25-30% of tubewell water are available in may-June.Static level of ground water rised and dependency on submersible pump increased. In 2012, 2013, 2014 and 2015 annual rain fall were recorded as 729, 1134, 1475 and 1626 mm respectively in the study area. About 28 wetlands or beels with 1821 hectore of total land in puthia. Among them, only 890 hectore area were used for cultivation in 1990 and 1739 hectore are using for cultivation in 2014. Now a trend has been started to digging pond in the beel area. In 1990, cultivation mostly depend on organic manure but in 2014 use of chemical fertilizer has tremendously increased. In 1990 most of the people used only 5-7 items of pesticides on their cultivable land on the other hand the use of pesticide practices increasing in the study area up to 15-22 items in 2014. There were about 31 species of fruit plants, 29 species of timber plants and 43 species of medicinal plants were commonly found in 1990, but in 2014 it is only 22 species of fruit, 18 species of timber plants and 25 species of medicinal plants are commonly found respectively. A total of 184 plant species were identified in the six study villages during last one year 2014. Among the 184 plant species, 45% weed species, 15% vegetable, 12% fruits species, 10% timber species, 4% spices and 14% medicinal plants species. In case of wild animal, in 1990 about 21 species were seen in the study area but depletion of wild animals are occurring in the study area, Only about 14 species rarely found in 2014. About total 34 species of birds recorded and were common in 1990. But only 25 species are common in 2014. About 39 species of fish were common in 1990. But only 21 species are common in 2014. A total of 75 animals species were identified in the six study Villages during last one year 2014. Among the 75 animals species, 3% livestock, 4% poultry, 3% pet animals, 19% wild animals, 33% birds and 38% fishes species. Findings of this study that cultivation/land used pattern (50%), Use of chemical fertilizer (9.2%), Use of pesticide etc. (16%), Irrigration (4.4%), Hybrid, HYV and Exotic plant (4.5%), Use of modern agriculture technology (5.2%), Habitat distruction (3.4%), Road constration and urbanization (4.7%) and others (2.6%) were the causes of loss of biodiversity mentioned by the respondents. But there occur depletion among the species in time to time and up to 2014 which is mostly done by anthropogenic activities. During data collection from questionnaires, it was found that most of the farmers did not taken the training of proper use of insecticides, pesticides, weedicides and chemical fertilizers. But the have the realization to the necessity of sustainable Biodiversity conservation. Additionally impacts of agriculture practices on sustainable biodiversity afford an opportunity for researchers to make further researches, particularly about the conditions in which native and diverse species will flourish.