Soil erosion losses for key Goa crops less than or close to national average: ICAR

PANAJI: A day after TOI reported that severe soil erosion is likely in parts of Goa, ICAR-CCARI on Wednesday said soil erosion losses in cashew, mango and coconut cropping systems were less than or close to the national average.
ICAR-CCARI cited several studies carried out in Goa over 15 years.
“Soil erosion losses in Goa vary from moderate to extremely severe classes.The national average soil loss in India is 15.59 t/ha/year,” said director of ICAR-CCARI Parveen Kumar. The permissible soil loss limit for India is 11.2 t/ha/year.
Kumar said that soil erosion losses in cashew, mango and coconut cropping systems were estimated to be 24 t/ha/year, 12.6 t/ha/year, and 10.5 t/ha/year, “without any conservation practices.”
The institute said that for cashew crops, conservation measures reduced the runoff by 44.5%, soil loss by 47%, and NPK (nitrogen, phosphorus, and potassium) loss by 60.2%.
“Cashew litterfall, which starts during November-December, covers the soil surface and acts as a physical barrier to runoff and reduces soil erosion losses,” said Kumar. “Further, the leaf litter helps to develop a conducive environment for micro-flora and -fauna.” He added, “Improved organic matter and microbial activities lead to an increased infiltration rate. This will result in improved soil moisture conservation and groundwater recharge.”
As for mangoes, conservation measures reduced soil loss by 83% and runoff by 53% over control. This recommended measure, on average, reduced the NPK loss by 88.6%. As far as coconuts are concerned, circular trenching reduced soil loss and runoff by 76% and 34%, respectively and the NPK loss by 78.2%.
“The cultivation of crops like cashew, mango and coconut reduces soil erosion,” said Kumar. “However, the adoption of soil and water technologies developed by ICAR-CCARI further helps to reduce soil erosion loss and improves soil health.”