No abstract

Kerala state in India has rich bio-diversity and tropical rain forests and is spread in 13 agro-ecological zones under the humid tropics. Rainfall decline (annual as well as monsoon), increase in temperature and climate shift towards lesser humid zones within the humid climate are the notable characteristics of the state. Cropping system changes, as well as changes in the production of spices and plantation crops in Kerala, were analyzed from 1952-53 to 2018-19. Area and production changes of various crops in the Idukki district have also been studied and presented in this paper. The average temperature in Kerala has risen by 0.65 °C from 1956 to 2014. In Idukki high ranges, the maximum temperature is increasing, and the minimum temperature is declining, resulting in a widening of temperature ranges. Such a scenario may adversely affect the thermo-sensitive crops, which may need urgent attention as these crops are grown in the forest-agro-ecosystems across the Cardamom Hill Reserve (CHR) of the Idukki district. Deforestation, the shift in cropping systems, declining wetlands, and depletion of surface and groundwater resources had deepened the adverse effects of floods and droughts on spice and plantation crops. Therefore, there is an urgent need for proactive steps on a short and long-term basis against the climate change risks for the sustenance of crop production both in terms of quality and volume.

The allelopathic effects of eight selected agroforestry tree litter on the sprouting and early growth of the understorey tuber crop, elephant foot yam (Amorphophallus paeniifolius) were examined during 2014-’15. Litter leachates at 2% concentration and litter mulch were used for the study and it was found that the effects of litter mulch were significant on sprouting and seedling growth while with the leachate, significant effects were recorded only on shoot growth and leaf production. The effects varied with species, tamarind and wild jack recorded maximum inhibition both as leachate and mulch. Litter of rubber, mango and jack showed stimulatory effects thus bringing to light their potential to be used as organic inputs in elephant foot yam cultivation.