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BIODIVERSITY
Contents: Importance of biodiversity Causes of biodiversity loss Biodiversity erosion in aquatic ecosystem Impacts of some agricultural production techniques on biodiversity Diversification in agricultural systems: bringing back biodiversity and lessening the impact of climate change Enterprising in Integrated Farming System Literature Cited/References Importance of biodiversity Biodiversity is the term used to describe the variety of life at all levels, from genes to species and ecosystems. The continued presence of biodiversity is fundamental for ecosystems to be in a position to provide the many services upon which humanity depends. Ecosystem services include the provision of food, water and shelter, regulatory services including flood and disease control, cultural services such as spiritual and recreational benefits, and supporting services such as the cycling of nutrients (MEA, 2005). Biodiversity is very important in the agriculture sector. Bioversity International (2012) listed important reasons why agricultural biodiversity matters. Agricultural biodiversity matters because first, agricultural biodiversity is the foundation of agriculture. It is the source of genetic material that is vital to future generations. When a species or the diversity within a species is lost, we also lose genes that could be important for improving crops, promoting their resistance to pests and diseases, or adapting to the effects of climate change. Secondly, agricultural biodiversity can provide a cost-effective way for farmers to manage pests and diseases. Using diversity allows farmers to limit the spread of pests and diseases without investing in high chemical inputs. Third, agricultural biodiversity gives farmers options to manage climate risks. Fourth, agricultural biodiversity can provide smallholder farmers with more crop options and help buffer the effects of extreme events such as droughts or floods. Fifth, agricultural biodiversity can play a role in sustaining soil health, food and habitat for important pollinators and natural pest predators that are vital to agricultural production. Traditional knowledge and culture is often based on local species diversity and its use. Lastly, agricultural biodiversity plays an important part in maintaining cultural identity and traditional knowledge; whether it involves passing on knowledge about local medicinal plants and traditional recipes, to being a key feature of cultural rituals and festivals. Agricultural biodiversity can
also contribute to health and nutrition. For example, minor millets have protein levels close to that of wheat and are rich in B vitamins, calcium, iron, potassium, magnesium and zinc. Causes of biodiversity loss There are various causes of biodiversity loss. Habitat conversion or the conversion of forests, grasslands and wetlands to farmland results in loss or fragmentation of habits. This in turn contributes to degradation of ecosystem services such as flood and erosion control. A survey to assess genetic erosion in populations of coconuts ( Cocos nucifera L.) was conducted by Uddin et al. (2005) in three provinces in Northern Luzon, namely, Pangasinan, Isabela and Nueva Vizcaya and in Quezon, a province in Southern Luzon, Philippines. The decrease in coconut area and number of palms were the indicators used to determine the extent of genetic erosion. Genetic erosion was noted in all provinces except Pangasinan. In the three provinces, the coconut farm size was reduced by 14% to 20% and the number of palms in Quezon and Isabela decreased by 20.90% and 4.91%, respectively. The reasons for the decrease in coconut area and number of palms were poor marketing system, the low market price of the nuts, soil erosion and crop conversion. Pollution or the excess or inappropriate application of crop inputs such as fertilizers, herbicides and pesticides is another cause of biodiversity loss which can result in damage to surrounding areas via run- off or spray drifting into surrounding areas. According to Bhattacharyya et al. (2015), the indiscriminate use of pesticides together with sewage sludge and composted municipal wastes leads to contamination of soil and water with toxic substances and heavy metals. Heavy metal pollution is due to improper disposal of industrial effluents and use of domestic and municipal wastes and pesticides. Some commercial fertilizers also contain appreciable quantities of heavy metals, which have undesirable effects on the environment. Indiscriminate use of agro-chemicals, such as fertilizers and pesticides, is often responsible for land degradation. Another cause of biodiversity loss is the inappropriate cultivation techniques. For example, farming in hilly areas without due regard for contour consideration can lead to extensive erosion during rainy periods while over-cultivation of fragile soils can lead to wind erosion, soil compaction and loss of soil micro-organisms – all factors contributing to reduced productivity of the affected land; Introduction of invasive species is one. New species introduced for crops, shade or pest control can become invasive and spread much
development, coastal erosion and storm surges associated with climate change (PCHM, 2009). BFAR-NFRDI-PAWB (2005) reported a declining trend in the state of most coastal and marine ecosystems in the Philippines due to such factors as overfishing, destructive and illegal fishing activities, increase in population and human settlements near coastal areas, infrastructure development and pollution. However, the same report highlights the lack of comprehensive and historical data to better understand the state of this ecosystem. Impacts of some agricultural production techniques on biodiversity Agricultural production techniques contribute to degrading biodiversity. Leibel (2011) listed some examples of agricultural techniques contributing to biodiversity loss. For example, rainfed agriculture which is the dominant production system in many developing countries relies on naturally occurring rainfall for crop productivity. Rainfed systems are frequently transformed into irrigated lands that compete with vegetation for ground water. Shifting Agriculture is another factor leading to biodiversity loss. Producers clear a patch of forest for agriculture and/or to establish land tenure. One of the leading causes of biodiversity loss from deforestation and habitat destruction. Nutrient loss in primary and secondary forests from burning to release nutrients. Shifting agriculture leads to continuing biodiversity loss as plots of land are abandoned in favor of new areas leading to loss of forest genetic diversity. FAO (1994) stated that in the past, shifting cultivation was a sustainable form of land use, at a time when low population densities allowed forest fallow periods of sufficient length to restore soil properties. Population increase and enforced shortening of fallow periods has led to it becoming non-sustainable. Shifting cultivation is found in the hill areas of northeast India, where it is a cause of water erosion and soil fertility decline Pastoral system is also one. Cattle-rearing is the leading cause of tropical deforestation in Latin America (Boucher et al., 2011). Increasing demand for meat produce has led to significant deforestation rates for the development of agro-pastoral farming systems. Loss of endemic cattle breeds that are drought-tolerant, adapted to harsh environments. Alkemade et al. (2010) stated that biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food.
Lastly, monoculture plantations. These reduces genetic diversity on farm and typically associated with increased use of agrochemicals. Older varieties with disease tolerance slowly disappear since farmers use modern high-yielding varieties. Diversification in agricultural systems: bringing back biodiversity and lessening the impact of climate change Diversification in the field has lots of benefits to farmers and to the farm itself. According to Lin (2011), crop diversification can improve resilience in a variety of ways: by engendering a greater ability to suppress pest outbreaks and dampen pathogen transmission, which may worsen under future climate scenarios, as well as by buffering crop production from the effects of greater climate variability and extreme events. Such benefits point toward the obvious value of adopting crop diversification to improve resilience, yet adoption has been slow. The following are examples of diversification which may benefit farmers under climate change. Polyculture Polycultures is the growing of two or more crop species and wild varieties within the field. It has a lot of benefits like disease suppression, climate change buffering, and increased production. In the study conducted by Carbonell (2015) in Camarines Norte, Philippines, cropping pattern employed by most pineapple farmers is multiple cropping, specifically intercropping, rotational cropping, and fallowing. Soil nutrient and weed management of most respondents is conventional: inorganic fertilizers and chemical based, respectively. Pest control management by most of the respondents is of the alternative method. Overall, pineapple farmer respondents were found to be practicing alternative farming methods (incorporation of sustainable practices). Today, there is now a growing interest in the use of organic material as fertilizers, mainly for two reasons. First is agronomic such as improvement of soil physical properties, balanced nutrient supply for crops and a sustainable cropping system. Second is economic such as efficient use of wastes and by- products and higher consumer demand for organically grown products. In fact, organically fertilized pineapple was analyzed and the results were promising. Agroforestry It is believed that agroforestry provides multiple benefits to people living in the uplands. First, establishment of agroforestry systems
Genetic diversity in monoculture Pest and disease outbreaks is the most threatening phenomenon. Application of chemical pesticides is the number one solution nowadays. However, the bad consequences are also well known. One of the effective and environmental friendly ways to control diseases is to apply ecological approaches in modern agricultural systems by which heterogeneity is employed for sustainable pest control. Creating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, maintaining high yields with the minimum fungicide applications. Whether such an approach is universally applicable for random rice variety combinations and what is the variation pattern of the diseases under intercropping still remains unclear. Guang-yu et al. (2016) conducted two-year large-scale field experiments involving 47 rice varieties/lines and 98 variety-combinations to compare the occurrence of rice blast in monoculture and intercropping plots at multiple sites. In the experiments, the plant height of the selected traditional varieties was about 30 cm taller, and their life cycle was 10 days longer, than that of the improved rice varieties. The monoculture included either traditional or modern rice varieties grown in separate plots. The intercropping included both traditional and modern rice varieties planted together in the same plots. Results from the field experiments under natural disease conditions demonstrated significant reduction for rice blast disease in intercropping plots, compared with that in monoculture plots. Traditional rice varieties had a much greater increase in the efficiency of disease control than modern varieties. In addition, substantially lower values of variance in the blast incidence and severity was detected among the variety combinations in intercropping plots than in monoculture plots. Based on these results, they concluded that the intercropping or mixture of rice varieties greatly reduces the occurrence and variation of rice blast disease in particular variety combinations, which makes the intercropping system more stable and consistent for disease suppression on a large scale of rice cultivation. Enterprising in Integrated Farming System Integrated farming system (IFS) promotes biodiversity at the same time promoting sustainability. The advantages of IFS include pooling and sharing of resources/inputs, efficient use of family labor, conservation, preservation and utilization of farm biomass including nonconventional
feed and fodder resources, effective use of manure/animal waste, regulation of soil fertility and health, income and employment generation for many people and increase economic resources. It improves space utilization and provides diversified products. The IFS is part of the strategy to ensure sustainable use of the natural resources for the benefit of present and future generations (Preston, 1995). The basic aim of IFS is to derive a set of resource development and utilization practices. Which lead to substantial and sustained increase in agricultural production (Kumar and Jain, 2005). Integrated farming system are often less risky, if managed efficiently, they benefit from synergisms among enterprises, diversity in produce environmental soundness. An example of enterprising in India was studied by Sahoo et al. (2012) with the farmer practicing integrated farming (pond based) named Ranjan Kumar Bhuyan. He has taken various enterprises based on available resources in a 4,360m^2 area. The components were as follows (1) rice in the field and (2) fish in the refuge pond, trenches and also in the rice fields, (3) vegetables (radish, brinjal, okra, pumpkin, tomato, poi, spinach, coriander etc), (4) pomology (lemon, papaya, banana, guava, coconut, etc.) (5) agroforestry (teak was grown on dyke). Climbing vegetables like ash gourd, ridge gourd, country beans, bottle gourd, etc. were grown on the platform hanging over the trenches. The economic analysis of pond based farming system revealed that the gross income of Php 51,984.08 was obtained by investing Php14, 464.76. This system provided employment of 248 mandays with benefit cost ratio of 3.59. The net income from the pond based farming system was 37,558.38. The risk of economic loss in this system was minimum. Thus it is implicit that the entire concept of Integrated Farming System (IFS) through agroenterprise convergence revolves round the interactive use and efficient utilization of land, labour, capital cum available resources. An analysis of the enterprise distribution and economic profile of the model of IFS unit above concludes that pisciculture dominated pond based farming system with 4 broad components like crops, horticulture, fishery and allied non crop (mushroom, apiary, lac, etc.) can be advocated for the food security and sustainable livelihood support of small and marginal farmers.
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