Rodent damage to rice crops is not affected by the water‑saving technique, alternate wetting and drying

Rice farmers in Southeast Asia are hesitant to adopt the water-saving technology, alternate wetting and drying (AWD), for fear the practice will lead to increased rodent pest activity, consequently exacerbating yield loss. We examined the effects of AWD on the population dynamics, habitat use and damage levels inflicted on rice crops by the most important rodent pest of rice in Indonesia and the Philippines, Rattus argentiventer and R. tanezumi, respectively. Rice crop damage levels were not affected by the water management scheme employed. Rodent activity in rice fields was not influenced by water level. Both species tended to use the rice paddies over bunds regardless of water level, indicating that something other than water affects their habitat use, and we argue it is likely that the perceived risk of predation is the primary factor driving habitat use. Activity levels and damage inflicted by rodent pests on rice were not correlated. AWD had no effect on breeding and population dynamics of these species. Breeding of R. argentiventer is tied to the growth stages of rice, while available resource dictates breeding by R. tanezumi. Our findings clearly indicate that rice farmers in both Indonesia and the Philippines have no cause to reject AWD based on concerns that AWD would exacerbate crop losses by rodents. Given AWD is being promoted as a climate-smart technology for rice production in Asia and Africa, we strongly recommend its adoption without concerns that it would aggravate rodent pest impacts in lowland irrigated rice cropping systems

Alternate wetting and drying in Philippine rice production: feasibility study for a Clean Development Mechanism

Water-saving technologies such as alternate wetting and drying (AWD) provide a way to change practices to improve the livelihoods of many rice farmers and AWD is regarded as one of the more important rice cultivation methods that can dramatically save freshwater irrigation in this century. AWD not only conserves water but also mitigates greenhouse gas emissions. The global climate influence of gases, particularly methane, and resulting reduction in methane emissions by adjusted water management practice through AWD may provide the means for rice to adapt to water scarcity and at the same time mitigate greenhouse gas emissions. With these associated benefits, AWD technology could be harnessed for a Clean Development Mechanism (CDM). This paper will discuss the merits of AWD and explore the possibility of being a CDM for areas affected by water shortage in the Angat dam and reservoir. This document has three parts: - A literature review of AWD and CDM - An in-depth assessment of possible AWD dissemination in Angat reservoir - Appendices comprising documents that will be needed in the process of application and registration of an envis- aged CDM project in Angat reservoi