Soil rejuvenation through plants - Cultivator's Perspective

Dr Kreni Lokho / Lohrii Adai *

Plants are natural components in tropical ecosystem. Plant provides a wide range of service to human from firewood and construction materials, to fruits, nuts, gums, resins, fodder and medicines. They also render services such as shade, wind shield, aesthetic and spiritual value. The present study is carried on the Mao-Naga-an ethnic community from Manipur.

Fourteen respondents were selected through snowball sampling and interviewed with a semi-structured questionnaire. It is necessary to note here that the respondents are all cultivators in occupation with more than twenty years of experience in both terrace and swidden fields.

Prior to the study, Prior Informed Consent is taken and in compliance with the Nagoya Protocol of Access and Benefit sharing for ethical research.

From the inception of the Forest Survey of India (FSI), the reports of FSI states that the forest cover in 1987 is 17,475 km2, after more than three decades (1987-2021), the forest cover in Manipur has recovered just 711.17 km2.

Comparing the previous 2019 reports with 2021, the forest cover in Manipur loses 464 km2 in a span of three years which is slightly smaller than the entire district of Bishnupur district (496 km2).

This calls for increasing forest covers by introducing fast growing plants and plants that can regenerate soil fertility in the shortest time. The article also aims to educate the general public to boost their crops in both the swidden and terrace farming (quality and quantity).

The study is undertaken based on the two farming practices (swidden and terrace field cultivation) in the Mao-Naga community. According to the respondents, the following are the plants known to increase top soil regeneration in the swidden cultivation.

Alnus nepalensis: [Common Name (CN): Nepalese alder and Local Name (LN): eposii]: Majority of the respondents observed that the plant are fast growing and also known to increase soil biomass.

Kreni, Pfokrehrii (Punanamei village), Athisii, Besii, Kaikho, Kapani, and Neli, (Kaibi village) suggested that the leaves of the plant degrade easily and the region where the plant grows, it can regenerate soil biomass in the span of 5-7 years. Even though the knowledge is known throughout the community, plantation of sapling in the swidden fields is still on the wane.

Ageratina adenophora: [CN: Crofton weed; LN: Japan pro]: The plant is native to Mexico and rated as class 4 noxious weed. The invasiveness of the plant species is manipulated by the Mao-Naga community for increasing the soil biomass. According to Ashuli and Puni (Shajouba village), plants are trimmed/cut during the last week of November and continue till January. The degraded biomass is used as fertilizer.

Saurauia napaulensis: Native to South Himalayan and China. The plant bears large broad leaves and also used as fodder for cattle. According to the Pfokrehrii (Punanamei), Adaso, Besii, Athili and Kapani (Kaibi) the plant provides huge biomass, results in increasing the soil fertility.

They are also fast-growing plant. According to the author observation, plant population around the region is degrading due to the plant has no commercial value nor the edible fruits are commercialized in the local market.

Ficus semicordata: [CN: Drooping figs, LN: Chiidoshii] Native to south Asia. According to Athili and Lokho (Kaibi), the soil around the root region is blackish and fertile. According to the author observation, the fertility of the soil might be attributed to its fruits. The ripen fruits falls off and degraded, resulting in the soil fertility.

Polygonum molle and P. runcinatum: The Genus of Polygonum is considered as invasive by the community. These plants are tapped by the community for enriching top soil.

According to Adaso, Asakho, Besii and Daikho (Kaibi) plant sheds its leaves and also degraded easily. Some species grown in the terrace fields are allow to undergo retting during ploughing and helps in easy tilling during the next season.

Many of the Polygonum species can be also propagated through stems. Thereby, the plants can be introduced in the barren lands or along the sides of newly constructed roads for soil enrichment.

The leaves of the plant are introduced in the wet terrace fields for retting. According to Kreni, Pfokrehrii, (Punanamei), Ashuli (Shajouba), Besii and Kaikho (Kaibi) told that the after the first ploughing the leaves are stomped down on the mud and allow retting.

After 3-5 days depending on the weather conditions, the leaves are completely degraded leaving a black sludge. It is said that the crops yield and growth of the crops is faster in such fields. They also observed that the leaves of paddy exude dark green leaves compared to the paddy without leave retting.

The common plants which are introduced in the paddy fields are Melia azedarach [CN: Chinaberry tree; LN: otu shiilashii or Chiithosii], Butea buteiformis [CN: Shrub butea; LN: Chiikho vii], Zea mays [CN: Maize; LN: Pithotho].

According to the respondents, care should be taken not to plant the paddy right before the leaves started retting because rotting of the leaves infects the roots of the paddy, leading to death.

Albizia chinensis [CN: Chinese albizia; LN: Movu sii]: The leaves of the plant are also added in the wet terrace fields. Kreni and Neli said that the fresh leaves are kept near the sapling of Capsicum chinensis (King chilly) for the growth of sapling and results in more yield.

The Mao-Naga community has extensive knowledge of plants and its uses because of its agrarian occupation.

According to research paper by Agrawal et. al, 2018, on the 'Importance of biofertilizers in agriculture biotechnology', due to ever increasing population, the demand of food supply has to be increased to 70 percent by 2050. The use of chemical fertilizers not only depletes the minerals and essential microbes but may results in lesser yield in the following years.

The respondents share similar opinion that the use of chemical fertilizers is said to harden the soil and difficult to tilled. Its hardening to see that many of these age-old traditions pass down by our forefathers are dying out and people nowadays look for alternatives which can reduce labour and energy.

For example, the use of chemical weedicides and fertilizers are use extensively in many villages. The state should adopt the policy of Sikkim as a role model that phase-out the use of chemicals and certified all farmland as organic.

The implementation of bio-fertilizers will sky rocketed the demand and supply for biofertilizers. It is a known fact that organic crops have great health benefits, eco-friendly, economic benefits, increase productivity and cost effective.