©2019 BY TARU NATURALS.

No-till sugar cane cultivation with alternate row irrigation, Belgaum, Karnataka, India

December 24, 2017

Background

Suresh Desai is a founding member of an Organic Farmers Club in Belgaum District of Karnataka, India. It has 400 members, some of whom are already growing crops organically, while others are in the process of shifting to organic farming.

Suresh was born in Bedkihal Village, Belgaum Dt. in a traditional extended South Indian family comprising 67 members. Since completing his matriculation, Suresh has been caring for the family property of 4.5 hectares, in an area where today sugar cane is primarily grown. For nearly a decade Suresh, as the manager of the farm, followed conventional practices relying on external inputs in the form of chemical fertilizers and pesticides. Just like most of the other farmers near Belgaum, he grew sugar cane, a high water-demanding cash crop, and tobacco.

Conventionally, sugar cane is grown in three-year cycles. A sugar cane crop takes about 18 months to mature, it is then harvested and a ratoon crop is left to grow. After cutting the canes, a lot of trash remains in the fields. Some of this is used as a roofing material, while the rest is burnt, usually at night. Burning can damage the roots, but there is a good initial re-growth of the ratoon crop since the nutrients in the trash become soluble by burning. The burning also helps in pest control, ensuring that pest problems of the standing crop do not contaminate future cops. However, what most farmers do not realise is that most of the nutrients contained in the ashes are leached out with the first irrigation, and as the water demand of the sugar cane crop is high (recommendations are that it receives 100 percent water cover, effectively flooding the crop), this can be a serious problem. After the harvest of the ratoon crop, the field is left fallow until the next planting cycle which may be after six months or a year.

Suresh's yields for sugar cane were 75 to 90 tonnes a hectare, very much like that of his neighbours. However, Suresh started having second thoughts as he noticed a process of degradation unfolding in his fields. The crops became increasingly affected by pests and disease, the soil gradually lost its native fertility and structure, and water supplies were dwindling. In short, the family property was on the decline.

What most farmers do not realise is that most of the nutrients contained in the ashes are leached out with the first irrigation.

Initial experiments with organic practices

At that point it occurred to him that in fact there were plenty of residues available mainly from the sugar cane fields that were hitherto considered of no particular use. With the escalating prices for external inputs, Suresh began venturing into experiments that would ultimately bring a drastic change in the cultivation of his sugar cane fields. Suresh says that the driving factor for shifting away from chemical farming was economic. The understanding that organic materials were available and that the use of these could reverse the process of degradation of the family property pointed the way out.

At first he tried composting the residues and using this to fertilize his sugar cane crop. In this way he was able to reduce the inputs of chemical fertilizers to a certain extent, however, composting involved a lot of labour for collecting, mixing, watering, then turning and finally hauling the organic matter back to the fields to be ploughed in. Suresh reasoned that if the work of shifting organic matter to and from was avoided, it would mean a considerable saving in time and labour.

Suresh's system enables a reduction in water usage by 75 to 80 percent in comparison with the conventional usage.

This brought him to the next step wherein organic residues were incorporated in situ in the fields that produced them. With this method, Suresh was able to reduce the application of chemical fertilizers by 50 percent, while maintaining the same production levels. However, problems related to irrigation in heavy black cotton soils started to appear. Groundwater levels had declined drastically while the fields became slowly gorged with water and laden with salts. Suresh came to understand that irrigation itself was responsible for this slow but steady spoilage of the soils.

This brought him to the third change in his thinking and agricultural practice. He imagined that if the trash obtained after the cutting of the canes could be kept "on" the soil as mulch, evaporation losses would be significantly reduced, the need for irrigation would diminish and the salinization problem would eventually be overcome.

By keeping all the trash on the fields as mulch, Suresh found that irrigation became very difficult since the trash obstructs the flow of the irrigation water. The idea that the trash could be kept in one row and that the water could be provided in the next row became the solution to this problem. He calls this the "one-in-two" irrigation system. Moreover by connecting two parallel irrigation rows with a perpendicular trench at the ends, he made watering the fields much easier (see Figure below).

In one go Suresh Desai was able to reduce his irrigation requirement by 50 percent, and after harvesting the cane, the remaining trash was gathered in the row that was used previously as the irrigation channel.

Continuing in this way for three years, Suresh observed a remarkable improvement in the soil and an amazing increase in soil life. He also started using a soil conditioner and introducing green manure between the rows of cane and found that using chemical fertilizers became unnecessary. He also saw that his crops were healthy and that there was no more need for chemicals to combat pests and diseases. Furthermore, because of the intense soil life and the action it manifested on the soil, Suresh hazarded the idea that cultivation could perhaps be stopped altogether, so he did. His fields have not been ploughed or turned up for the last 5 years. The only soil work left is the periodic maintenance of the irrigation channels.

Zero tillage and reduced irrigation - the impacts achieved

Ever since ploughing was stopped, the water-retention capacity of the soil improved further. Consequently, irrigation frequency was reduced from once every 10 or 12 days to 20 or 25 days, thereby achieving a further saving of 50 percent in water requirement.

Suresh discovered that the cane crop thrived even when irrigation was further reduced to one in three rows. This meant yet another saving of 25 percent of water. Suresh is at present experimenting with pushing the lower limits of irrigation to one in four rows.

On the whole, Suresh's system enables a reduction in water usage by 75 to 80 percent in comparison with the conventional usage.

Soil fertility

Soil fertility in Suresh Desai's farm is maintained by the combined effect of four factors:

  • reduced irrigation;

  • trash composting;

  • green manuring;

  • soil conditioning.

Reduced irrigation: by reducing irrigation, salt build-up is minimized. It also restricts nutrient losses due to leaching. Soil compaction as a result of excessive irrigation is also avoided.

Trash composting: when trash is kept on the fields as mulch, evaporation of moisture is greatly reduced. The soil is protected from the direct impact of the elements and hence soil life develops extremely well. Soil quality and structure improve. Finally as the trash decomposes, nutrients are taken up by the roots again to make new growth.

 

Green manuring: green manure is, according to Suresh, a source of nitrogen and other elements compensating for the high carbon content of the trash.

He uses a combination of many plants for his green manure mix. He also believes that with this combination the ill effects of the monocropping pattern without rotation, as is the case in his sugar cane fields, can be overcome. Furthermore, his green manure mix consists of plants and crops that were grown before when dry farming was practised, it re-establishes equilibrium in the soil, which these plants help to maintain.

The green manure mix is generally made up of cowpea, mustard, amaranth, coriander, horse gram sesame, sunnhemp and chickpea, amongst others. Initially Suresh used to prepare a green manure mix which was inter-sown between the lines of cane using a bullock drawn implement. Nowadays the green manure seeds are mixed with clay and manure and formed into balls (large pellets). These balls are then just dropped in the trash at regular intervals between the canes. The green manure plants are cut once or twice at 30 to 40 day intervals.

Soil conditioning: to enhance the decomposition of the sugar cane trash, Suresh applies a conditioner on the fields at the time of irrigation in the form of slurry. Consisting of 250 grams of wet yeast and 500 grams of jaggery, mixed with 10 kg of cow dung and a little water, this enhances the proliferation of fungi, hastening the breakdown of the fibres of the trash. In fact after application of this slurry an enormous development of fungi, sometimes forming a white cake, can clearly be seen. This has, according to Suresh, a great influence on the water-retention capacity of the soil and makes it possible for him to reduce irrigation to only once in 25 days.

With the application of trash, green manure and the conditioner, the soil has become very fertile, healthy and sweet. The proof of this is his canes which grow fast, are vigorous and sturdy and problem-free.

Other impacts

  • Suresh's canes mature in 8 sometimes 8.5 months compared to 11 or 12 months in the conventional system.

  • Sugar recovery is much better in his canes than in chemically grown ones. Though he sells his canes together with the other farmers (making it difficult to give exact figures), Suresh has been told that the recovery of his canes is 11.5 percent whereas for the other farmers it is a maximum 11 percent.

  • His canes are very healthy and no problems of smut or grassy shoot, the main problems of the area, have occurred in his fields for the last five years. Neither chemical nor botanical sprays are needed.

  • Suresh obtains an average yield of 100 tonnes per hectare. His neighbours who follow the conventional methods obtain on an average 110 ton per hectare, but his costs are far less.

  • Suresh claims that with his method, the amount of irrigation water needed is even less than that consumed by sprinkler irrigation.

  • As minimum tillage is practised and there is no fallow or replanting of sugar cane, labour requirements have been reduced.

  • Suresh's focus on natural biological cycles as the main input to the farm has caused an impressive increase in soil biodiversity. This biodiversity is now working for him, maintaining yields.

  • The use of traditional dry farming crops in his green manure mix functions as a gene pool for rapidly disappearing species.

Financial impacts

Suresh Desai has been able to drastically reduce his cash investment per hectare. This is mainly due to a 30 percent reduction in labour and reduced water requirement. The comparative figures are as follows:

 

 

The use of traditional dry farming crops in his green manure mix functions as a gene pool for rapidly disappearing species.

These figures for Suresh Desai's investments, as well as other farmers, are averages. In some cases, in the conventional practice when farmers want to push their yields above 120 tons, the cost of inputs per acre can soar up to Rs 24 700 per hectare. Investments in the case of organic cultivation also increase if additional external inputs are used.

A continuous process of learning and design improvement

Suresh's farming experience so far has led him to develop an altogether new plan for his sugar cane cultivation. The plan is still under consideration and is only at the "design" stage. The new farming design features:

  • increased spacing between settes and rows;

  • stimulation of tillering by the "snapping method";

  • intercropping with dryland food crops between sugar cane.

In the conventional practice, the space between the rows of cane is 0.75 to 1 m, and within rows the space between the seeds or settes is about 15 cm. This close planting system requires up to 7.5 tonnes of seed materials per hectare. With Suresh's new design, only 1 000 to 1 250 kg of seeds per hectare will be required. The improved plan comprises a paired row technique with a distance of 1 to 1.25 m between the paired rows, a 30 cm foot distance between the settes within a row and a 2.5 to 3 m distance between a set of paired rows (see Figure below).

Suresh is confident that with increased spacing as recommended in his new design, more tillers will appear. He also uses an effective technique to stimulate tillering. This involves snapping off the first shoot after a 45-day period of growth. Suresh already has some experience with this snapping-method, which was a traditional practice in his area.

Initially Suresh recommends the growing of green manure crops in the larger space between the paired rows. But the ultimate aim is to use this space to grow other "dryland" food crops, such as grains, oilseeds and pulses. These "dryland" crops will benefit from the moist soil environment created by irrigating the canes.

Suresh estimates he will be able to maintain the same cane yield with this new system. In any case he will have reached a very high level of efficiency in the utilization of irrigation water. Suresh sees this as his main achievement and it is a great source of contentment and meaning in his life as a farmer. Notwithstanding all his innovations and savings of water, Suresh has been able to maintain his yields at 75 to 100 tonnes of cane per hectare.

Constraints of the System

 

 

Although Suresh recycles all organic residues as trash compost, he uses the same cane variety as other farmers (Nr.7/40) which is apparently a low-trash variety. He does not use any other extra manures such as farmyard manure, compost, bagasse or pressmud or any foliar sprays such as cow urine or vermiwash which could improve his yields considerably.

Labourers are not easily willing to work in his fields because of the fear of snakes and scorpions that are believed to live under the mulch. This is in spite of the fact that no untoward incident of that nature has ever occurred during the eight years that Suresh has been farming this way. However, now that more and more farmers are following his method this constraint is gradually disappearing.

Diffusion of Suresh's methods                                                                                         

At present 250 neighbouring farmers are following Suresh Desai's method, or variations thereof. A total of 300 hectares are under this system of farming.

How did he reach out to other farmers? His extension approach is in fact very simple.

Suresh organizes farmer days, inviting farmers to come and see his fields. His whole concept is explained and discussed right there in the sugar cane field and if some farmers are convinced about changing, the steps to be taken are clearly spelt out. For most farmers, Suresh advises the use of some compost and oil-cake initially. This is to give the organisms needed for the processing of the trash a good start or boost. The oil-cake serves as a trap for the fungi.

Not all farmers stop using chemical inputs completely. Some have not gone beyond the `one-in-two' irrigation method. On the other hand, some of the farmers who have adopted his method have obtained much better results then Suresh himself! Many variations of the method can now be seen in and around Bedkihal. Some farmers use trash composting with drip or sprinkle irrigation, some use extra organic inputs such as pressmud or bagasse, while some still use a small quantity of chemical inputs. The number of farmers taking up the method is growing slowly but steadily.

Why has no-till, alternate row irrigation not spread beyond Belgaum-Bedkihal?

First it may be that only farmers in the immediate surroundings have access to his fields and his concrete example. Second, only recently have a few mentions been made in the local newspapers and in some local radio programmes about Suresh Desai's innovations. Audio-visual materials, such as slides and video are now being prepared about his methods so that a much larger public can be reached. Suresh Desai is also an active founding member of his "Organic Farmers Club" and has participated in numerous workshops and farmers days throughout the country.

Last, it may be that farmers who visit Suresh's fields might be disappointed, as no "bumper" crops will be seen to satisfy their bewildered imagination. They will see crops that look sturdy and remarkably healthy, but for the rest the yields will seem nearly the same as theirs. There is a tendency to evaluate the `success' of organic practices in terms of the "yields" alone. This is misleading because what is important is not only the "net profit", but also the "quality". As Suresh uses few external inputs, his investments remain low while his yields are average, but his net profit is higher than a conventional farmer.

Higher yields can be obtained and this is well illustrated by the case of Satish Kulkarni. He applies a good dose of bagasse or pressmud on top of the trash and can in this way obtain yields up to 175 tonnes per hectare.

But Suresh is happy and satisfied with his results. He does not risk anything, nor does he need a heavy cash investment. All in all, Suresh has stable and assured returns.

As Suresh uses few external inputs, his investments remain low while his yields are average, but his net profit is higher than a conventional farmer.

What lessons can be learnt from Suresh's experience?

Throughout Suresh's process of experimentation he learnt a variety of lessons, all of which are fundamental to organic agriculture and the sustainable use of the natural resources:

  • Excessive irrigation caused many soil related problems including salinization, water-logging and a resulting build-up of pest and disease problems.
  • Suresh discovered through a process of trial and error that these problems can be easily overcome by:
  • incorporating the sugar cane trash into the soil, increasing the organic matter content, improving the water retentive abilities of the soil, reducing the need for irrigation.
  • maintaining a cover on the soil in the form of cover crops and mulches, lowering evaporation and reducing the build-up of salts.
  • By reducing the need for irrigation, Suresh saw a major improvement in soil structure and increased decomposition, releasing nutrients more quickly into the soil. These biological cycles and processes could replace the chemical inputs that were previously used.
  • The use of green manures increases fertility and overcomes the problems associated with continuous monocropping of sugar cane.
  • So active was the soil in Suresh's farm that minimal tillage was necessary, the soil organisms did it all for him. Suresh planted all his seeds in dung pellets avoiding the need to work the soil.
  • Such an active soil reduced pest and disease problems, his sugar cane grows healthily and sturdily.
  • As the soil began working for Suresh, this cut down on labour demands by an estimated 30 percent.
  • Suresh also learnt that conversion to his system cannot be done at once, but needs to be a step-by-step process.

From Suresh's experience, it can be seen that a diverse soil biodiversity is a powerful tool for organic agriculture and can substitute external inputs almost entirely. As Suresh demonstrates, individual farmers are clearly an important source of innovation and should be supported in their experimentation and in the diffusion of their successes. Furthermore, farmers should be encouraged not to stop experimenting once they have achieved one result, but should continue striving to improve their farming systems in the face of an ever-changing agro-ecosystem.

As the soil began working for Suresh, this cut down on labour demands by an estimated 30 percent.

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