(from the Semi-annual report October 14-April 2015)

Summary:

A field study on the effects of different irrigation levels on the growth and yield performance of corn, garlic, finger pepper, peanut and ttomato under MMSU condition is being conducted at the research farm of Mariano Marcos State University, Batac City, Ilocos Norte under San Fernando soil series. The study started on November 2014 and hopefully will end on August 2018. 

The study specifically sought to: 1) determine the theoretical water requirements of corn, garlic, finger pepper, peanut and tomato using the modified FAO-Penman method; 2) determine the actual crop water requirements of corn, garlic, finger pepper, peanut and tomato; 3) compare the actual and theoretical ET crop water requirements of corn, garlic, finger pepper, peanut and tomato; 4) determine the growth and yield performance of corn, garlic, finger pepper, peanut and tomato as affected by different irrigation schedules based on Readily Available Moisture (RAM) depletion; 5) determine the peoper timeing and frequency of irrigation of the specified crops; 6) determine water-yield relations (production functions) of corn, garlic, finger pepper, peanut and tomato; and 7) determine optimum amount of water for the production of the specified crops. Irrigation level treatments consists of the following: 41-50% of Readily Available Moisture (RAM), 51-60% of RAM, 61-70% of RAM, 71-80% of RAM and 81-90% of RAM which were laid out in a Randomized Complete Block Design (RCBD) with three (3) replications.

Results on the growth and yield performance of the different crops studied as affected by frequency of irrigation for the two season set-up shows some variations specifically for the finger pepper, peanut and tomato. Another season set-up of the study was on-going for additional data to validate earlier results and to have a conclusive data.

(from the Detailed Proposal)

This project will revolve around the assessment and optimization of water consumption of corn, garlic, finger pepper, peanut and tomato. First, theoretical crop water requirements of corn, garlic, finger pepper, peanut and tomato will be estimated using different climatic data multiplied with the crop coefficients (kc) of the said crops. Climatic data will be gathered through the installation of Automated Water Station (AWS) and it will be supplemented with the data coming from MMSU-Agromet Station. On the other hand, crop coefficients (kc) of the said crops will be based on kc values generated through lysimeter studies conducted at UPLB and it will be supplemented by kc values published by FAO. Simultaneously, actual crop water requirements will also be determined through an interview complemented with an actual calibration of discharge rate of pumping used by neighboring farmers. Physical and chemical characteristics of the soil together with quality of irrigation water to be used will be considered throughout the duration of the study as these parameters affect the crop evapotranspiration. Theoretical crop water requirements and actual crop water requirements will be compared.

An experimental set-up planting major rice-based crops like corn, finger pepper, peanut and tomato at the MMSU experimental farm will be established for a minimum duration of 3 years. Treatments will be on irrigation scheduling based on different depletion of readily available moisture or available water capacity. Regular monitoring of soil moisture using soil moisture kit will be done to attain the desired depletion of readily available moisture. Growth and yield performance of corn, finger pepper, peanut and tomato will be gathered and analyzed as affected by the different irrigation schedules. Results to be generated will provide proper timing and frequency of irrigation.

Lastly, optimum crop water requirements will be determined through crop water production function utilizing the results on the effect of different irrigation.

Soil samples will be collected at the proposed experimental area and farmers field every before the establishment of the different crops. Physical and chemical properties will be evaluated prior to the set-up of experimental plot as these parameters affect percolation rate and thus influence crop evapotranspiration. Chemical properties will be analyzed using standard laboratory procedures. Total N, available P, exchangeable K, Organic matter, pH, bulk density and other parameters will be determined using standard methods of analysis. Apparent specific gravity and hydraulic conductivity will also be determined.

On the other hand, water quality on the source of irrigation water at the experimental area and farmers field will be monitored as salinity affects the absorption of water thus influencing crop evapotranspiration. Electrical conductivity will be used as an indicator of salinity since EC can easily be measured using a conductivity meter. EC, pH, temperature and TDS will be directly measured in the field while chemical properties will be analyzed using standard laboratory procedures.

Treatments. A land area of 450 m2 each for tomato, corn, garlic, finger pepper, and sweet sorghum, will be allotted and will be replicated three (3) times. Plot size will be 30 m2. The growth and yield parameters will be determined based on different irrigation schedules, which will be the treatments of this study. Furrow irrigation method will be used.