Development of Regenerative Tea Cultivation Models through Dual Approach of Soil and Plant Health Management towards Crop Sustainability, Soil Quality Development, Pesticide Reduction and Climate Change Mitigation: A Case Study from Lakhipara Tea Estate,

Abstract

Climate change is a reality and its impact on the tea plantations is apparent in the rise of pest intensity, higher agrochemical use, inconsistent crop yields, declining grand growth period, increased abiotic stress and various other challenges; that threaten long-term sustainability of the Indian tea sector. The urgency to adopt sustainable practices is increasing by the day but to gain time bound results a comprehensive focus encompassing soil and plant health development will be crucial. To deal with climate challenge head-on, the Indian tea industry is making changes at various levels of operations. The sustainable tea initiative at Lakhipara tea estate, was one such attempt by the Goodricke Group Limited in their Dooars tea growing region of West Bengal. The program was initiated in 2014 with an aim to reduce pesticide use, improve soil quality, and produce quality teas while sustaining crop yields, improving renewable energy use and lowering the carbon footprint. Adoption of Inhana Rational Farming (IRF) Technology and taking the essence from ‘Trophobiosis Theory’ of French Scientist F. Chaboussou, the program focused on management of soil and plant health. Three years evaluation of crop yields in respect of the budgeted crop, revealed on an average an excess of 78 kg/ha/year in the project area.  In rest of the garden area a contrasting crop loss of 118 kg was recorded per ha during the same period. The higher crop performance positively correlated with the  higher nutrient use efficiency which was 17.7 percent higher in the project area (NUENPK : 8.86) as compared to the general garden area (NUENPK : 7.53), which reflected the impact of plant health management towards enhanced nutrient uptake, assimilation and utilization. Assessment of pesticide usage, revealed up to 77% decrease in usage in the project area during 2014-16, as compared to the pre- project year. Comparison with pesticide usage of the Dooars tea growing region during this same period, indicated a 62% lower Crop Pesticide Pollution Index (CPPI) in the project area. The finding indicated a 52 to 77% reduction in the accumulated toxicity potential of the applied pesticides in the project area; thereby accrediting safer tea development under this program, when adjudged in terms of pesticide residue. Assessment of soil quality revealed an overall eight percent increment in Soil Fertility Index (FI) value, with significant improvement in soil microbial activity potential (MAP) values i.e., by almost four times. The finding pointed towards the favourable impact of soil health management primarily through Novcom composting towards enhancement of soil microbial interactions. Post three years of experimentation the overall Soil Quality Iindex (SQI) value increased by 6% in the project area. The finding corroborated a concurrent 6.72% increase in the soil organic carbon stock during the same period. Reduction in use of non- renewable inputs viz. chemical fertilizers and pesticides in the project area was indicated by approximately 40 percent enhancement in energy use efficiency and energy productivity post the assessment period. Carbon assessment in terms of kg CO2 equivalents/ kg made tea (using ACFA version 1.0) indicated approx. 65 to 70 % lower footprint in the project area, primarily due to 20 to 30 % reduction in chemical fertilizers and 60 to 70 % reduction in the use of synthetic pesticides. The results indicated that while integrated soil management is the pre-requisite criteria towards rejuvenation of soil health and for restoration of the habitat for predators, it does not play a direct role in reducing the pest pressure and simultaneously the requirement of pesticides. Physiologically activated plants/ bushes on the other hand; due to their higher nutrient assimilation capacity and efficient protein synthesis are always lesser susceptible to pest attack. Hence, focus on activation of plant physiology can reduce the plant- pest interaction leading to a natural reduction in the requirement for pesticides vis-à-vis the pesticide usage.