Manohar is an MSc in Soil Sciences. Was interested in social work right from school days. The Government slogan for social work in his childhood days was Jai Jawan, Jai Kisan. Could not join the army to become a Jawan, so he became a Kisan. We started our charcha by discussing the role of science in agriculture. According to Manohar, agriculture’s basic sciences have been very well covered by nature. Very little is required to support her. Plants are nature’s creation – and nature will take care of its own. What does a plant need? Very little. We think that a tree is built from nutrients drawn from the soil. But if you weigh a plant, you will find that 99.5% of the weight is made up of C, H and O – something that is not got from the soil – but from the air.
In the culture of agriculture, technology is frugal science used to find local solutions for local problems using local material. The problem is that most of us are fascinated by the complexity of solutions. Manohar draws an interesting analogy for our beliefs in technology. Today’s tractors and harvesters are gold knives that we are using for cutting butter. Farmers can be equally well off using simple threads for cutting their butter. A plant needs 13 nutrients in the 0.5% balance weight. Our hunger for fertilisers and the agri industrial economy is based on these nutrients. All the agri tech fight today is to supply this minuscule 0.5% of plant components. We feel God like when we fertilise the plant, yet we make little difference.
Life in plants derives from moisture in the air. Kharif crops depend on rainfall – but rabi crops depend on moisture. Interestingly, even trace minerals are present in the air that surrounds plants. And we need to understand the threat to moisture from global warming. Global warming is really very local. Manohar gave an interesting example to drive home this point. In earlier days, it would take many days for our jeans to dry on a clothesline. Nowadays our jeans dry up overnight. Even in Konkan, where we expect high humidity, the weather has changed. From November to May if you woke up in the morning there was so much dew there, you could be mistaken to think that it rained overnight. Now you can sleep in the outdoors in April in Ratnagiri – and not get soaked. The world is becoming a drier place!
How is this dryness affecting agriculture? Let’s say there is a plant which is pumping up water at the rate of 2 litres a day. In order for the pump to work, 2 liters of water has to evaporate every day. Because of global warming, this evapo-transpiration rate has now become 3 litres a day. But the pump at the root is only 2 HP, so it continues to pump up 2 litres of water. The deficit of 1 litre is shrinking the plant biomass. Plant leaves shrivel. Yields come down. The process of converting flowers to fruit requires moisture, a Relative Humidity of more than 50%. Mangoes and tur crops in Maharashtra in the last 2 years have flowered, but not fruited.
Greenhouses seem to be a solution to the problem of retaining moisture. Closed polyhouses have an ostensible advantage that the temperature is maintained in an optimal range. They also are supposed to reduce the incidence of pests and disease – and give you the convenience of harvesting whenever you want. Another advantage is that you can grow species that would normally not grow in a certain climate. But Manohar believes that green houses are an inappropriate technology for Indian conditions. He questions the wisdom of growing alien plants in Indian environments. The no pest polyhouse is a myth. There are actually specific pesticides for polyhouses – which cost much more than normal and are also required to be used in larger quantities. Manohar’s study of greenhouses also found that the temperature range inside greenhouses (difference between min and max temperatures) was more than the range outside. So polyhouse manufacturers now suggest farmers put in foggers inside the greenhouse. First light the fire – and then water it! 18 to 35 C is a good growing temperature for plants. Most of our states have this temperature range. So why do we need greenhouses? Only because manufacturers have vested interests in selling polyhouses that end up costing tens of lakhs of rupees per acre.
Manohar’s favourite bugbear is drip irrigation. Roots need to go as deep into the ground as the plant’s height. We don’t worry about roots. Out of sight is out of mind. The primary purpose of a root is anchoring, secondary is water transport and tertiary is to transport minerals through this water. Minerals are important for the plant immunity – so without them they are more susceptible to disease. Minerals are found in parent rocks. Roots have biological water sensors at their tips. As the water table drops, the roots go down, anchoring the plant more firmly and also reaching the layer of the parent rock – and access to minerals. What drip irrigation does is to misdirect the roots – as these water sensors detect the easier source of dripping water, making the roots go up instead of down. Drip irrigation ends up pampering the plant. Now, we have to work for the plant, not vice versa.
If drip irrigation is spoon feeding, air irrigation is breast feeding. And with the same results in plants that we see in humans. Water is absorbed by the leaf through osmosis of air moisture. In summer rain, even if soil does not become wet, the leaves are fresh. Instead of drip irrigation, Manohar strongly recommends rain guns and micro sprinklers to increase local humidity in fields and orchards. A micro sprinkler produces small droplets which can remain suspended in the air for a long time. A rain gun is an extremely cheap polyhouse, A rain gun can throw 15,000 litres of water an hour – but it needs to be run only 5 to 10 minutes every evening! Manohar goes on to predict that very soon we would be seeing sprinklers on city roads, where humidity levels have dropped to as much as 10 to 15%. After all, sustaining human health also requires a Relative Humidity of 40 to 50%.
All life has two growth phases: vegetative growth and reproductive growth. Vegetative growth requires nutrients. Reproductive growth requires hormones. By focussing on nutrients, we are creating plant pehalwans, who will remain bachelors throughout their lives. Gomutra (cow urine) helps in hormone creation in plants. Manohar considers the cow gobar and urine to be much more important than milk. An interesting observation that he made: In adivasi areas, taking milk from a cow is considered a sacrilege. Our wise forest friends raise cows only for their ‘waste’ products!
From cows, the discussion veered towards our underground friends – the earthworms. Earthworms don’t have urinary tracts, but it they have a kidney like organ, which takes out waste material from their body. This serves as a lubricant to help the earthworm navigate underground. Worm worked soils have burrows formed by the earthworms. Water passing through these passages washes the nutrients and hormones from these burrows to the roots to be absorbed by the plants. This principle is applied in the preparation of vermiwash. Vermiwash is considered by most people to be fertilisers, but they are more useful for the hormones. For those of you who may be unaware, hormones are literally worth their weight in gold. Good vermiwash is golden in color. Putting vermiwash in transparent bottles changes its color and makes it turbid. So we need to store vermiwash in colored bottles.
And here is where we talk again of an interesting adivasi connect. Manohar is not an armchair scientist – the fields and forests are where most of his work happens. In one of his projects he had a team of adivasi women working with him. Every day, they would eat their dabbas, and the dabbas were rinsed and the rinse and waste food was thrown in one corner of the field. A very interesting observation made by Manohar was to see chillies, brinjals and tomatoes coming up in the corner. Vegetable seeds retained their germination potency even after cooking. Manohar was working with vermiwash on that project. One day, he put some of the vermiwash on these saplings. The result was disaster – all the saplings were dead within a day. So there must have been some power in the vermiwash. The sexual organs of these hermaphrodites secrete a fluid which has an antifungal property. This is what we use in order to help retain the health of plants during fungal attacks.
In the end, Anil wanted to know how a farmer can cut costs. Manohar believes that the reason costs are high is because farmers view themselves as producers. They need to change this point of view – and become nurturers. The best technologies for India are frugal ones – or ones that cost nothing. He gave a very interesting example of grass management. The hariyali grass is very difficult to eradicate because of its runners. Manohar used to stay in Khed Shivapur and one day while weeding out grass while talking to a guest, without realising it, he knotted a hariyali grass. A few days later he realised that this grass dies on knotting it. He believes small innovations like this can even happen in primary schools like Peepal Tree!
Manohar can be contacted @ 90110 38065
Charcha question ideas for Manohar Khakke
Why do plants shed leaves?
The respiration process in plant releases water into the atmosphere. How is this water got back into the leaf through the air?
If organic farming takes less inputs, why is organic food sold at higher rates in the market?
What is the relation between beauty and nutrition in fruits?
Should an organic farmer allow pests and weeds to exist in her field?
Does it make sense to have mixed species fruit orchards?
Should trees be pruned?
Can air irrigation be done for grains and vegetables?
Instead of mulching, can we have a base layer of vetiver grass or something like that covering the field?
What is the mechanism for mineral absorption by the roots?
Drip irrigation reduces pesticide consumption as weeds do not get water, yet you are against it. What are the disadvantages of drip irrigation?