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This study assessed the applicability of Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) as rainfall input in watershed modeling using the Soil and Water Assessment Tool (SWAT). The CHIRPS and ground-based rainfall data were used to calibrate and validate the SWAT model in four selected watersheds from each of the four Climate Types in the Philippines. The SWAT performed adequately with CHIRPS across sites during calibration (R2 > 0.74, NSE > 0.71, PBIAS between −6.92 and +12.92, and RSR 0.68, NSE > 0.67, PBIAS between −4.24 to 13.13, and RSR < 0.57). The SWAT models of small watersheds with rainfall inputs from both weather stations and CHIRPS exhibited almost similar results. The ground-based rainfall from one station was not enough to achieve reliable SWAT simulations of streamflow in relatively large watersheds. The CHIRPS proved to be an adequate rainfall source for watershed modeling and can be used as an alternative or supplementary SWAT input in small and large watersheds. This study may serve as a useful reference for water resources managers, policy, and decision-makers in dealing with sparse rainfall monitoring network that is of utmost importance in water resources planning.

Summary This study used Maximum Entropy (MaxEnt) to explore potential environmental determinants of Fusarium wilt occurrence on banana in south-central part of the Philippines. Different variables representing topographic, bioclimatic, and edaphic features of an area were tested against data of Fusarium wilt occurrence. Based on the results, precipitation during the driest month, precipitation during the wettest month, precipitation of the warmest quarter, slope, and elevation were the most important variables for predicting the probability of Fusarium wilt occurrence on banana. Results also suggest that among the variables tested, precipitation had the major contribution to the occurrence of Fusarium wilt.

Climate change is expected to affect crop production directly and indirectly due to changes in crop suitability, decrease in productivity, and higher incidence of pest and diseases. In the case of banana, change in suitability and distribution of Fusarium wilt due to climate change can pose a major threat on its production system. Being a major dollar earner for the Philippines, these threats can greatly affect the country’s economic and food production system. This study assessed banana suitability and the potential distribution of Fusarium wilt in the Philippines under current and future climate condition using fuzzy logic and maximum entropy approach. Based on the results, climate change might have limited impact on banana suitability in the country. But the projected changes in rainfall in the future can increase the areas that are favorable for Fusarium wilt occurrence. From 21% under baseline climate condition, favorable areas for Fusarium wilt in the Philippines is estimated to increase to 27% covering 91.2% and 28.5% of the country’s highly and moderately suitable areas for banana, respectively. Such coverage accounts for approximately 67% of the country’s total harvested area for banana.

This study evaluated and downscaled (using Delta Method) Climate Research Unit time series (CRU TS) monthly precipitation gridded data in the Philippines. Based on the results, raw CRU TS data tends to underestimate (average percent bias = 0.89%) precipitation for most months of the year while downscaled CRU TS showed the opposite (average percent bias = − 2.99%). Overall both raw and downscaled CRU showed acceptable performance when compared with the observed monthly precipitation record. However, downscaled CRU TS data showed better accuracy (lower Mean Absolute Error and Root Mean Squared Error) and better performance (higher Nash–Sutcliffe Efficiency) compared with the raw CRU TS data. On the average, the computed evaluation statistics for downscaled CRU TS data were 79.87 (MAE), 144.56 (RMSE), and 0.43 (NSE) while 87.82 (MAE), 163.69 (RMSE), and 0.30 (NSE) for raw CRU TS.

This study assessed spatial pattern of trends in monthly rainfall and temperature in the Philippines using Climate Research Unit time series data. Based on the results, there are significant trends in monthly rainfall and temperature in the country. On the average, monthly rainfall in the country is increasing by 0.34 mm/year. In the case of monthly temperature, the average increases per year were 0.008 and 0.019 °C, for maximum and minimum temperature, respectively. In terms of proportion, larger portion of the country showed significant trends in monthly temperature (> 80%) compared to rainfall (

The aim of this research was to evaluate the use of manufacturing wallboard paper scraps as an alternative bulking agent for dairy cattle manure composting. The characteristics of the composting process were studied based on the changes in physico-chemical parameters and final compost quality. Composting of dairy cattle manure with wallboard paper was performed in a 481-L cylindrical reactor with vacuum-type aeration. Rapid degradation of organic matter was observed during the thermophilic stage of composting due to high microbial activity. High temperature and alkaline pH conditions promoted intense ammonia emission during the early stage of composting. The number of mesophilic and thermophilic microorganisms were found to be affected by changes in temperature at different composting stages. The total nitrogen (N), phosphorus (P), potassium (K), and sodium (Na) concentrations of the mixture did not change significantly after 28days of composting. However, the presence of gypsum in the paper scraps increased the calcium content of the final compost. The wallboard paper had no phyto-inhibitory effects as shown by high germination index of final compost (GI=99%).

A thermophilic–mesophilic sequence of composting was compared with continuous thermophilic composting in a small-scale laboratory reactor. Dairy cattle manure was allowed to self-heat adiabatically for one week prior to individual temperature treatments at 20, 37, and 55 °C. Preliminary self-heating was carried out to naturally activated indigenous compost microorganisms to attain thermophilic condition. Microbial activity during composting was monitored by measuring oxygen uptake rate (OUR). Total active microbial biomass was measured using the adenosine triphosphate (ATP) bioluminescence technique. Organic matter degradation was determined by measuring the volatile solids content of compost samples. Results showed that composting at 55 °C promotes the rapid degradation of organic matter as shown by high cumulative oxygen uptake. Composting at 37 °C also exhibited high microbial activity probably due to degradation of complex organic compounds. Microbial biomass was found to be high at 20 and 37 °C, indicating larger microbial communities at lower compost temperatures. Organic matter degradation analysis revealed no large differences in the final solid degradation rate at 55 and 37 °C. The study suggests the importance of a thermophilic–mesophilic sequence in composting to maximise the extent of organic matter degradation.