At a time when decreasing soil fertility especially due to indiscriminate use of chemical fertilisers and prolonged cultivation of commercial crops has become a cause for concern among farmers, legume vegetables have turned out to be a boon for addressing this issue.
Scientists feel that growing the legume vegetables at least once in a season will help in increasing soil fertility as they have the capacity to fix atmospheric nitrogen through their root nodules. This reduces the use of chemical fertilisers like urea and ammonium nitrate.
Of course, growing legume crops for the natural fixation of atmospheric nitrogen was an age-old practice of traditional farmers.
But the process has now been discontinued mostly by those growing commercial crops due to lack of awareness.
Dr. T. S. Aghora, principal scientist at the Indian Institute of Horticultural Research located at Hessarghatta near Bengaluru who has been working on legume vegetables, says various studies have shown that growing legume vegetables can increase soil fertility that will in turn increase the yield of regular crops by a range of 10 to 15 per cent.
A study by IIHR has showed that growing legume vegetables along with coconut plantation can help increase coconut yield by about 10 per cent, he says. Similarly separate studies by various institutes and organisations too have indicated an increase in paddy yield by over 10 per cent when legume vegetables are grown as a rotational crop and an increase of 10 to 12 per cent in sugarcane yield when legume vegetables are grown as an intercrop.
Cultivation of all the crops including cereals and regular vegetables will get benefitted if the legume vegetables are grown once a season, Dr. Aghora notes.
Apart from fixing atmospheric nitrogen, the legume vegetables also help in increasing the organic content of the soil as they produce huge quantum of foliage that gets added into the soil. In addition to this, they also enhance the water-holding capacity of soil, he points out. They have a positive impact on human health too as these protein-rich legume vegetables can help fight protein and energy-deficiency induced malnutrition.
The advantage of legume vegetables is that they are all short-duration crops whose life cycle will get completed within 70 to 75 days. Hence they can be grown either as a rotational crop or as an inter-crop between the regular commercial crops depending upon the requirements.
In fact the legume vegetables start yielding within 45 to 50 days of sowing and fit into any cropping systems, the scientist points out.
Of late the scientists are focussing on developing high-yielding and diseaseresistant varieties which can fetch good incomes to farmers.
These short-duration varieties help enhance the incomes of farmers not just because of increase in their yield, but also due to the fact that they reduce the spending in terms of application of fungicides and pesticides.
The IIHR itself has released 24 different improved varieties of legume vegetables in the crops of French bean, garden pea, dolichos bean, and cow pea while various other research institutes and agricultural universities too have come out with their own varieties.
In fact some of the legume vegetable varieties go beyond the conventional concept that they are meant for the consumption of common people residing mostly in rural areas as they are gaining popularity in niche urban markets.
Such popular varieties include the ‘whole pod edible’ variety of garden pea.
Named as Arka Apoorva (Arka stands for river Arkavathi on whose banks the IIHR is located), the variety’s entire pod is edible as the pod walls do not have fibrous layers. This reduces wastage.
The pods of Arka Apoorva can be eaten either as fresh salad or after cooking and frying. The agricultural scientists feel that these whole pod edible peas present an opportunity for Indian farmers to explore their potential in the country’s niche urban markets.
Similarly there are garden pea varieties which have resistance to rust and powdery mildew diseases. Also, there are yard long beans varieties like Arka Mangala which is a climber that produces pods with a length of 75 to 80 cms that are extremely popular in niche market.
(For details contact Dr. T.S. Aghora, Principal Scientist, Division of Vegetable Crops, Indian Institute of Horticultural Research (IIHR), Hesaraghatta Lake Post, Bengaluru-60089, Phone – 080-28446140-43, Mobile – 9986100079; email: email@example.com)