Fighting salinity by reviving traditional rice varieties

By Anitha Reddy on 14th May, 2019

Hit by crop failure due to increased salinity in soil, owing to water surge in the natural tanks, farmers of the Tumkur1 and Chitradurga areas of Karnataka are reverting to cultivation of traditional saline tolerant paddy in the hope that it would feed them.

The fields of farmers in the region that adjoins the tank command area was rendered saline due to stagnation of water. Farmers here have always faced salinity problem but had coped with it by growing traditional saline tolerant varieties that they had conserved for generations. But in the last few decades the situation has turned grave and the salinity in the soil has increased tremendously. Farmers say that with the changes in agriculture the salinity has increased in the soil and the introduction of high yielding varieties to problem soils, with the aim of increasing production, has not only resulted in yield failure but has also contributed to the genetic erosion of traditional landraces. Intensive agriculture practices, years of monocropping and more importantly indiscriminate usage of chemicals has left the soil infertile. Earlier farmers practiced crop rotation and grew crops using traditional methods but now the younger generation of farmers lack the understanding to cope with saline soil and do not have the knowledge to use alternate crops or methods to overcome the situation.

With cultivation patterns changing since the 1970’s the salinity has increased. Now the soil has no fertility and has become very hard and growing any crop here is posing a huge problem. The salinity in the soil is pushing farmers to grow the saline tolerant traditional crops their forefathers cultivated, says Mallikarjun Hosapalya of Dhanya, an organization working in Tumkur District. He says, “The high-yielding paddy dies soon after being sown in the fields. As the pH level in the soil increases with saline conditions and with low rainfall, there is leaching of calcium and automatically there is increase in sodium, which leaves salt deposits. The sodium comes to the surface and makes the soil more saline. Farmers can grow only if the salinity is low but due to low rainfall the salinity has increased and only traditional paddy varieties can tolerate it”.

Some farmers have modified and adapted alternate techniques as a coping strategy to deal with the problem of salinity. But not much has been done with regard to the yield performance of the varieties. They are familiar with local varieties and these have many positive characteristics - taste, price, and milling value are better than that of the HY varieties, though yield is less compared to rice grown in other areas. But its sustainability requires awareness and some technical involvement to increase the yield.

Sahaja Samrudha,2 in collaboration with Dhanya3, and with participation of knowledgeable farmers, has evolved a reliable approach of collection, evaluation and systematic cataloguing of available saline tolerant rice varieties. This was initiated for more than twenty- five varieties that were collected from a single region. Sahaja Samrudha has combed the entire coastal belt of Karnataka and collected the salt tolerant varieties,i.e. the Kagga varieties that are very popular and highly salt tolerant. The collected germplasm has also been distributed to farmers for being cultivated at target sites. On-farm conservation was undertaken mainly to improve the performance of varieties that yield less due to mixture in the varieties. Participatory crop improvement selection has been found to be more effective for selection and development of these varieties. “No doubt, on-farm conservation of germplasm by farmers will save the traditional landraces for problem soils and will maintain the evolutionary processes and guarantee continual supply of germplasm”, says Dr. Devkumar, a scientist at the University of Agricultural Sciences (UAS), Bangalore .

 

Forgotten types of indigenous rice varieties can offer a home grown solution to the increasing soil salinity. Karnataka state has many saline tolerant traditional rice varieties that are high in nutritional value and have medicinal properties, and most are resistant to extreme drought conditions, diseases and pests and are popular for their taste. Documentation of collected varieties in relation to the cultivation practices, crop management, and manure management was carried out along with the farmers by Sahaja Samrudha and Dhanya in the initial phase of the programme. A number of trials were conducted to check if they could withstand salinity. These varieties were grown using natural inputs such as organic manure, and no chemical fertilizers or pesticides were used.

As Ajjanna Nayaka of Hosahalli in Pavagada taluk, who is growing Sanna vadlu rice variety for the past 40 years, says, “this is a fine grained variety, infact the grains are of superior quality than sona masuri variety. Crop duration is 4 months and yield is about 20 to 25 bags per acre4, superior in taste and very soft when cooked”.

Some of the other significant saline tolerant varieties identified during the exercise by Sahaja Samrudha and Dhanya are :

Picha neelu – This is a most popular saline tolerant variety, with crop duration of 4½ months, and grows 4 to 5 feet in height. It has good cooking quality and the grains are grayish black and white in colour and yields about 20 to 25 quintals per acre5.

Beli picha neelu is highly tolerant to saline conditions of soil and grows within 4½ to 5 months. A unique method followed by the farmers for good yield is to broadcast the germinated seeds directly on to the main field. For good germination, the seeds are dried well and then germinated. This yields about 25 to 30 qt per acre and is very tasty when cooked. It is popular among the farmers of Madakasira taluk.

Thokapichaneelu - Thoka means tail in Telugu, as the grain has awns on both side, hence the name ‘Thokapichaneelu’. Duration of crop is 4 ½ months and yield is about 20 to 25 qt. per acre.

Paddy varieties like Bilithopu vadlu, Kasanella are unique and highly saline tolerant, these grow in places where salinity problem occur due to erratic rainfall.

Choluchangi is also known as Koralu changi. Tip of the grain has awns6 and grows profusely with one application of farm yard manure. Kasarnellu, Bilitokavdlu, Kari tokavdlu, Bilipichanellu, Pichanellu, Jowguri have a crop duration of 4 to 5 months and yield about 20 -25 bags per acre. The grains are bold and long and are cultivated in Chitradurga and Pavagada. Sannanellu and Tokepichanellu are small and fine grain varieties. Mullubatha, Chintapolavodlu, Karichannangi, Bilichannangi, and Cholu channangi are medium grain varieties, grown in Sira and Pavagada region.

As rice is one of the major food crops, development of cultivars with enhanced salt stress-tolerance will undoubtedly have a positive effect on food production. As soil salinity tolerance of rice is a complex trait consisting of several physiological characters, research about the development of rice varieties tolerant to salinity is meagre. Hence, reviving cultivation of traditional saline tolerant varieties and developing rice varieties that are appropriate to prevailing local conditions is imperative. If breeders work together with farmers there are possibilities for developing appropriate varieties, while maintaining and enhancing biodiversity. These would be far more relevant and superior to the new saline tolerant GE varieties being created, in the formal research systems, that may not be appropriate to prevailing local conditions. Is genetic engineered rice that is tolerant to salinity a necessity, when our farmers for generations have developed varieties that are tolerant to saline and drought conditions?

 

Endnotes1 The Tumkur district is the third largest district in the state, next only to Gulbarga and Belgaum. Tumkur falls under the semi arid zone of Karnataka, which is considered as one of the most backward districts. The district average rainfall is 688 mm per annum but it is sporadic, erratic and inconsistent with an average of 34 to 54 rainy days in a year. All the taluks were declared as drought prone (meaning inconsistent rainfall) and the average rainfall recorded in past 10 years is 744 mm