Say- there are two tomato in front of you, one of them are fresh, medium in size, color is normal. another is larger, redder, genetically modified (GM), produced with using more fertilizer, pesticide, herbicide etc. Which one will you pick? If you ask me, it makes no sense of me to pick the second one. Sustainable agriculture is this kind of theme. But if we are really being concerned about our food, health and diet, we should know about sustainable agriculture extensively. Think about it. The well-known covid-19 has been existing with us during march. Have we ever stopped consuming food! It’s a never-ending process. So why are we indifferent about our food consuming process as food and agriculture related to each other inextricably?
Sustainable agriculture is farming in sustainable way keeping the ecological balance, which means cultivate the crop and raring the livestock in a minimal effect or zero loss of the environment. There are four sub-sectors of agriculture. Sustainable agriculture combined those sectors and sustain the ecological balance with a minimum effect. It’s very important to give equal priority of every component of nature that are related to our production system.
Soil is the first component in gaining sustainable agriculture as it is the basis for food, feed, fiber, biological organism, reservoir of mine, chemical elements and other ecological services. Soil is the surface of earth crust and it is the core component of agricultural development. It is the component where we do crop production, raring livestock, pasturing, forestry, infrastructure acts. It’s very important to start the sustainability from soil.
Tillage operation, chemical fertilizers, pesticides, herbicides disturb the harmony among the soil components. Tillage operation reduces the organic matter, biological organisms like earthworms, microbes, ants, and fertility of soil. The soil becomes dry before sowing seed, soil loses the nutrients like nitrogen, phosphorus, and other macromolecules. The symbiosis process hampers a lot. It decreases the infiltration rate of water causes runoff, soil erosion, volatilization and storing ability of soil. The soil become compact and attacked by pests and weeds easily. It can also cause a great hamper to the beneficial weeds, insects, frogs or living organisms thereby make a great danger in food chain and ecosystem. Tilling the soil results in dislodging the cohesiveness of the soil particle thereby inducing erosion. We should practice zero tillage or secondary tillage (less deep and loose only the upper portion of soil) to keep the soil fertile. When we use chemical pesticides, it causes a great hamper to the environment. They wash away with rain water and pollute the nearby pond, river and other water sources. It interrupts the rhythm among the ecosystem. We should try to use biological remedies like neem extract, beneficial insects, bait, or control the pest manually.
Moreover, when we apply chemical fertilizer such as nitrate, phosphate or sulphate fertilizer in the soil, most of the time it hampers the ingredients of soil. It mitigates the fertility of soil and the microbes and nematodes that help with a great extent of the crop health as well as soil. Finally, in that way the toxic elements enter into our body through food. Apply organic matter, farm yard compost (FYM), green manure (GM), compost, animal excreta, cow dung, crop residues, oil cake to keep soil healthy. Organic matter increases the microbial activity of soil. It increases the water holding capacity, nutrient exchanging capacity, retains moisture. It also provides the aggregation of soil, keep balance in soil temperature and reduces soil surface crusting, and compaction. Reduce the use of inorganic fertilizer. Biological nitrogen fixation is a microbiological process which adds nitrogen into the soil from the atmosphere. Nitrogen fixing system offer an economically attractive and ecologically sound means of reducing external inputs and improving internal materials. Symbiotic systems such as legumes and rhizobium can be a major source of N in most of the cropping system. Fabaceae family plants such as lentil, mung, chola, khesari, soybean, peanuts, alfalfa, etc. can contribute in fixing nitrogen in the soil. These are also called cover crops. Cover crops in agriculture are used to cover the soil from being erosion, keep the soil moist and help to maintain balance in nutrients and organic matter. One should also keep focus on cropping pattern and crop rotation in an agroecosystem. The cropping pattern and crop rotation should be selected in this way that the soil can conserve the maximal level fertility, moisture, nutrients, water and its pace.
As we are realized that every component is related to each other crucially, we have to take steps carefully. Not alone the Government, non profit organization and other institutions should help each other to spread the knowledge among the farmers as they are the real food hero. They should have to be taken into seminar and meeting to aware about sustainable agriculture and how to apply them. Field officers must give them proper knowledge and instruments before it’s too late.
Zakiya Hossain Moon, Department of Agriculture, Noakhali Science and Technology University.