The never ending demand for higher vegetable production for huge population has further led to a pressing demand of excessive application of fertilizers and pesticides. The higher application of chemical fertilizers and pesticides led to the adverse impact on the aquatic life, plants and animals. The areas making use of high levels of chemical fertilizers has shown a drastic contamination of ground as well as irrigation water with higher nitrate levels. Thus, continuous application of chemical fertilizer and pesticides results in degradation of soil, environment and resources. Therefore, a natural balance needs to be maintained with a sustainable strategy to produce more vegetables from limited resources with less application of chemicals in the form of fertilizer and pesticides leading to less detrimental effects to soil and environment. Organic vegetable cultivation not only offers one of the most sustainable farming systems with recurring benefits to long-term soil health but also provides a lasting stability in production by importing better resistance against various biotic and abiotic stresses.
“Organic agriculture is a unique production management system which promotes and enhances agro-ecosystem health, including biodiversity, biological cycles and soil biological activity, and this is accomplished by using on-farm agronomic, biological and mechanical methods in exclusion of all synthetic off-farm inputs”. In simple words organic agriculture is the farming system without the addition of artificial chemicals.
Why organic farming of vegetable crops?
- Vegetables are eaten fresh hence; any contamination (chemical residue) may lead to various kinds of health hazards.
- Vegetable growers largely are poor, small and marginal farmers.
- Decrease in land productivity due to an increasing use of chemical fertilizers and pesticides.
- Increasing cost of production by use of fertilizers, pesticides etc.
- High environmental pollution.
- Supply of vegetables free from chemicals and heavy metals.
- Organic vegetable cultivation can generates income through marketing high earning society, International and reducing production costs.
- Excessive use of chemical fertilizers as well as pesticides poses threat to the environment quality, ecological stability and sustainability of production.
- Properly managed organic farming system can increase the crop productivity and restore the natural base.
Organic vegetable production practices:
1. Conversion period:
Conversion of non-organic/conventional farm to organic farm takes minimum three years as transition period. The transition period starts with the date of signing the contract with certifying agency and after completion of first year produce can be sold as “in conversion to organic agriculture” and after two years annual crops can be sold as “organic”.
2. Soil and crop nutrition:
Most of the vegetable crops prefer a well drained loam or clay–loam soil with a pH range of 6.0 to 7.5. Some adjustment is required and is necessary before planting the crop for balanced nutritional requirements. The soil should also be tested for fertilizers and pesticides residues and contamination with heavy metal.
3. Soil fertility management:
Soil fertility should be high for successful organic vegetable production therefore the main objective in organic farming is to build up reserves of nutrients in the soil and to establish a system of nutrient cycling. The primary aim of organic farmers should be supply of crop and animal nutrients by implementing practices that take care of the soil, enhance soil life, and also conserve nutrients.
4. Variety and crop selection:
The essential criteria which need to be taken into consideration for variety and crop selection are seed and seedlings availability, resistance to pest and disease, suitable market for fresh produce supply, physiological characteristics and environmental suitability. The variety to be grown must be obtained from organically certified seed or seedlings. The variety should also be popular among the vegetable growers, high yielding, pest and disease resistance, and superior seedling vigour.
5. Crop rotation:
The legume crop like cowpea, beans, peas etc should be include in the crop rotation not only for improving soil fertility by fixing atmospheric nitrogen but also to increase the yield up to 30-35%
The covering of the soil surface with a layer of organic or inorganic material is known as mulching. It helps to modify soil environment, prevent soil erosion, check weed growth and enhance the activity of soil microorganism. Organic mulches which include plant or animal residue or by-products like sawdust, straw, animal manure, leaves etc increases the organic matter content of soil thus improving physical and chemical properties.
7. Weed management:
In organic vegetable production effective weed management is the most challenging aspects due to incorporation of local available organic manure to restore fertility of the soil. For higher organic vegetable production weed competition must be suppressed during the crop’s critical period.
8. Insect pest management:
The management of insect pests relies on various integrated management practices to maintain the pest population at economic threshold level. To avoid or reduce the risk of losses from pest’s infestation, it is essential to follow mechanical practices, crop rotation and develop planting strategies which includes time of planting, quality of planting material and source of planting material.
9. Trap crops:
Trap crops are also known as sacrificial crops which are planted to attract and hold insect and pests where they can be managed more efficiently thus reduces pest damage of the main crops.
10. Pheromone traps:
It is a type of insect trap that uses pheromones to lure insects. The most common types of pheromones used are sex pheromones and aggregating pheromones. These traps used to monitor, mass-trap, and/or disrupt the mating process of insect pests. Pheromone traps are effectively used for control of tomato fruit borer, brinjal shoot and fruit borer and fruit fly in cucurbits.
11. Biological control of pests:
In this method pest population is managed by natural enemies like predators, parasitoids and pathogens. There are various biological control agents which can be used for effective pest management in organic vegetable production