Palay (Freshly Harvested Rice)
Palay or Paddy rice, refers to the freshly harvested rice grains. Palay has a moisture content of about 20-26%, sometimes even higher. The moisture content must be reduced quickly to about 14%, otherwise, palay is quite susceptible to microbial attack and degradation.
Oil, gas, or conventional combustion of rice hull power existing mechanical rice dryers. The dryer and the fuel used are expensive and unaffordable to most farmers. Thus, Filipino farmers use sun-drying to dry palay (harvested rice). Sun-drying is slow, labor intensive and unreliable during the rainy season. Infestations, bird feeding, contamination and post-harvest deterioration decrease yield, quality and price of sun-dried palay.
- Total Palay Supply equivalent (darker blue filled with yellow square), the Total Milled Rice Supply (see darker blue filled square in Fig. 01) was converted to its equivalent as palay (paddy rice) to arrive at the Total Palay Supply equivalent (darker blue filled with yellow square) shown in Fig. 3a and Fig. 03b.
- Domestic Palay (Paddy Rice) Consumption equivalent (lighter blue filled filled with yellow inverted triangle), the Domestic (Milled Rice) Consumption (see lighter blue filled filled inverted triangle in Fig. 01) was converted to its equivalent as palay (paddy rice) to arrive at the Domestic Palay (Paddy Rice) Consumption equivalent (lighter blue filled filled with yellow inverted triangle) shown in Fig. 3a and Fig. 03b.
- Palay (Paddy Rice) Production (darker green filled with yellow circle) would be an original data based from estimates of the palay production before accounting for any post-harvest losses (PHL) and moisture content reduction before storage of the harvested palay. The Milled Rice Production (see darker green filled circle in Fig. 01 and Fig. 02) would be the final product of the Palay (Paddy Rice) Production, after the drying process, milling and accounting for post-harvest losses (PHL).
- Palay (Paddy Rice) Production with PHL (lighter violet filled with yellow square), this would be the actual Palay (Paddy Rice) Production after accounting for the reduction in moisture after drying and the total harvest losses (PHL) just before the palay is processed for milling.
- Imported Palay (Paddy Rice) equivalent (light yellow-brown filled yellow inverted triangle), the Imported Rice (see light yellow-brown filled inverted triangle in Fig. 01) was converted to its equivalent as palay (paddy rice) to arrive at the Imported Palay (Paddy Rice) equivalent (light yellow-brown filled yellow inverted triangle) shown in Fig. 3a and Fig. 03b.
- Palay (Paddy Rice) Export equivalent (lighter red filled circles), the Rice Exports (see lighter red filled circles in Fig. 01and Fig. 02).
Previous survey estimated the post-harvest losses (PHL) for rice to be about 15%, the extent of these post-harvest losses (PHL) is shown as the violet filled with yellow squares in Fig. 03a. The amount of these post-harvest losses (PHL) is in the order of several million tons of palay (paddy rice) production.
If these post-harvest losses (PHL) are not averted, it would require cultivating more rice to achieve a production level shown as the light violet filled with light red squares in Fig. 03b, just to achieve the equivalent of the reported "Palay (Paddy Rice) Production" if there were no post-harvest losses (PHL), shown as dark green filled with yellow circles in Fig. 03a and Fig. 03b. However, because available agricultural lands continue to diminish as they are converted for use to meet the demands of exploding Philippine population, achieving increased palay production through increasing land area is likely not an option in the near future.
The magnitude of these post-harvest losses (PHL) is several million tons (compare the various parameters in Figs. 03a and 03b, this will be explored in greater detail in separate presentation), an amount that if averted could reduce significantly the amount of rice imported needed to meet the domestic rice consumption.
To address this issue, one of the long term goals of Kalikasan-Philippines is to focus on reducing post-harvest losses (PHL). Kalikasan-Philippines (kalikasan-philippines.org) will assist further in the development of biomass powered rice dryers for reliable and fast palay drying; replacing conventional combustion systems with more efficient biomass gasifiers. We will investigate the efficacy of other agroforestry by-products to diversify the biomass sources suitable for gasifiers. We will investigate further design modifications of the dryer bed and gasifier. We will conduct physico-chemical experiments on the operation of the gasifier to improve energy efficiency of biomass utilization. We will improve the modularity and portability to optimize the use and decrease operational cost of the gasifier-powered rice dryers.
To address the high cost of rice drying systems, Kalikasan-Philippines will explore local mass production of post-harvest machineries, invest in equipment maintenance, and train a workforce to operate and maintain the post-harvest machineries. Kalikasan-Philippines will offer the package of equipment and services through a lease agreement with farmer cooperatives.
There is a scarcity of updated, authoritative and quantitative presentation of the post-harvest losses (PHL) as well as detailed accounting for moisture reduction during each stage from rice cultivation, post-harvest processing, milling, storage, transport and subsequent distribution to retailers before they reach the consumers.
The figure used here for the post-harvest losses (PHL) was from a FAO presentation published in the 1980s. The article has not undergone peer review to authenticate the methodology and the data collection. Further, not raw data was presented to substantiate the calculated post-harvest losses (PHL) at each stage of rice processing. The graphs presented here will be revised accordingly in the future once more authoritative and verifiable data become available from agencies like the International Rice Research Institute (IRRI), Philippine Rice Research Institute (PhllRice) and other educational or government agencies.