23 Mar 2023  |   06:00am IST

Soil erosion leads to major crop losses over last 15 years

ICAR-CCARI Goa study shows losses in cashew, mango and coconut cropping systems

Team Herald

PANJIM: Soil erosion in Goa has led to major crop losses over last 15 years. 

Studies conducted at the Indian Council of Agricultural Research-Central Coastal Agricultural Research Institute (ICAR-CCARI), Goa show losses in cashew, mango and coconut cropping systems, estimated to be 24, 12.6 and 10.5 tonnes per hectare per year, respectively without any conservation practices i.e. control, which are less or close to the national average soil loss.

To further reduce the soil and nutrient loss, the ICAR-CCARI, Goa has developed technologies for soil and water conservation measures in important crops such as cashew, mango and coconut based. 

Studies on cashew were conducted on 19 per cent slope from 2001-2013. In cashew, the soil and water conservation measure standardised (continuous contour trenching and vegetative barrier of vetiver grass) reduced the runoff by 44.5 percent, soil loss by 47 percent (reduced from 24 to 12.3 t/ha/year) and NPK (Nitrogen, Phosphorus, and Potassium) loss by 60.2 percent (reduced from 89.7 to 35.7 kg/ha/year) with increased soil organic carbon stock by 140 percent. 

Litterfall in cashew, which starts during November-December, covers the soil surface and acts as a physical barrier to runoff and reduces soil erosion losses. 

Further, the leaf litter helps in creating a conducive environment for the micro-flora and-fauna, such as earthworms. Improved organic matter and microbial activities lead to an increased infiltration rate. This will result in improved soil moisture conservation and groundwater recharge.

Studies on mango were conducted on 19 percent slope during 2002-2019, wherein, a soil and water conservation measure of continuous contour trenching (CCT) and vegetative barrier (VB) of vetiver grass  reduced soil loss by 83 per cent (reduced from 12.6 to 2.15 t/ha) and runoff by 53% than control (reduced from 42.1 to 22.3 per cent). This recommended measure on an average reduced NPK loss by 88.6 percent over control. Studies on coconut were conducted on 14 per cent slope during 2008-2019. 

In coconut, circular trenching reduced soil loss and runoff by 76 and 34 percent, respectively, which has reduced the NPK loss by 78.2 per cent over control. 

The cultivation of crops like cashew, mango and coconut reduces soil erosion however adoption of soil and water technologies developed by ICAR-CCARI further help to reduce soil erosion loss and improve soil health.

The ICAR-CCAR statement is following Information given by Union Minister for Agriculture and Farmers Welfare Narendra Singh Tomar in response to an unstarred question by Rajya Sabha MP Luizinho Faleiro, on Soil Health management studies in Goa.