Systems Approach to Efficient Field Machinery Utilization for Lowland Rice Production

Within the agricultural sector, there are wide variations in the level and pattern of energy use among various crops. To assess this energy demand, quantitative data on operating conditions is required for each unit operation. With the current increase in world population, energy consumption needs effective planning. One way to optimize energy consumption in agriculture is to determine the efficiency of methods and techniques used. This study was carried out with the ultimate aim of developing a model that could be used for estimating the energy consumption in a lowland rice production system and to predict the potential yield of rice from operational energy inputs and from quality indices of tillage and planting operations. Tillage systems obtained with factorial combinations of tractor forward speeds obtained from four transmission gear selections and three rotary tilling speeds were compared with respect to effective field capacity and energy requirements for implements used in the typical sequence for each system. The effects of the rotary tillage systems on irrigated soil properties in terms of changes in bulk density, cone index, plasticity index, aggregate uniformity coefficient and organic matter content were also investigated. Energy analysis for the entire production process included the operational energy consumption by field machinery and human labour, and the indirect energy accounted for by fertilizer, pesticides and seeds used, Functional relationships that allow the quantification of the different processes in the developed simulation model were formulated essentially through the use of secondary data and through curves fitting to some real data. Mathematical equations from agricultural machinery management and empirical equations were employed. Results from the tillage experiment indicate that differences in field capacity, and fuel and total energy requirements for each tillage system can be attributed primarily to many factors such as soil moisture, soil density, rotary tilling speed, and operation speed and depth. Average total energy inputs in the lowland rice production system (excluding irrigation energy) summed up to about 12225.97 ha-I. As main consumers of energy, fertilizer (7721 .O3 ha-'; 63.2%) and fuel use (2717.82 MJha- '; 22.2%) were identified. Human labour, pesticide, seeds and indirect energy for machinery use had marginal importance, contributing only 0.2%, 0.6%, 6.8% and 6.9%, respectively to the total energy consumption. Focusing on the operational energy consumption for the lowland rice production, the main energy use was in field cultivation activities (23 10.24 MJIha; 64.2%, planting included) and harvesting ( I 171.44 ~ J h a - '3: 2.6%). while spreading of fertilizer and pesticide had only little importance within total mechanization. Indirect energy use for mechanization took about 848.95 ha-' or 23.6% from total energy use for mechanization of 3595.87 h ha-'. Compared to total energy demand of 12225.97 h ha-I. indirect energy use for mechanization was even less important (6.9%). Average grain yield was 6470.8 kg ha-', representing energy output of 108321.75 mJha - 'that is, 96095.78 MJ net energy gain or 8.86 MJ output per MJ input. Energy input per kilogram grain yield was 1.89 M J ~ ~ -T' .h e simulation results obtained from the developed computer program regarding direct and indirect operational energy consumption in the lowland rice production were consistent with those obtained from the field study. The results of the study could serve as a guide to lowland rice farmers in other geographical locations in achieving their production goals. Improvements could be made through the application of the simulation model by figuring out the energy input requirements for all possible combinations of field operations for lowland rice production. It is suggested, as a consequence of this research, that paddy farmers in the Tanjong Karang Rice Irrigation Scheme of Malaysia and other schemes with similar operational conditions adopt the use of Gear 1 High and rotary tilling speed of 175 rpm for tillage operations. The application of this practice should reduce the excessive demand on fossil fuel energy which currently is very expensive and whose continuous availability is unpredictable. This will assist in the on-going campaign to minimize the flux of hard currency out of most developing and transition countries in the form of energy bills. The results and recommendations here are based on the available data on the current practices involved in the lowland rice production system of Malaysia and hence are useful for the current lowland rice crop planning and farm management practices

Irrigation energy consumption in a tropical lowland rice field

Available and limited water resources are seeing high demand from many sectors such as agriculture, industry and domestic households. In water allocation, the quantification of water in terms of energy used for water supply is more appropriate in terms of economic aspects. This study was undertaken to assess the embodied in irrigation for a lowland tropical rice production system. The irrigation energy requirements for the off and main cropping seasons were estimated based on crop water requirements at different cropping stages. Experimental results indicate that there are significant differences among the irrigation energy requirements of the various cropping stages, with the highest values of 4625.34 MJ ha-1 and 3843.93 MJ ha-1 observed for the mid-season stage in the off-season and main season, respectively. The off-season irrigation energy requirements for the rice variety MR 219 were found to be 32.6%, 26.8%, 20.3% and 271.7% higher than the mainseason for the initial stage, crop development stage, mid-season stage and late-s eason stage, respectively. There is a significant difference in irrigation energy requirement among the seasons and crop growth stages. Crop Water Use Efficiency (CWUE) in the off season (0.26 kg/m3 ) is higher than the CWUE in the main season(0.23kg/m3) which is attributed to better water management and yields during the off season due to water shortage. Irrigation energy productivity (IEP) of rice in the off season and the main season at Tanjong Karang is 0.26 and 0.29, respectively. In terms of irrigation energy spent, the main season shows better performance where a part of irrigation requirement is met by rainfall. Irrigation energy, CWUE and IEP can be used in decision making on the profitability of growing rice in different seasons

A national survey of rice (Oryza sativa L.) grain quality in Sierra Leone I: Perception of traders and consumers

As Sierra Leone approaches self-sufficiency in rice, against a backdrop of agricultural commercialization, the dynamics of the rice grain production and consumption will increasingly be driven by the quality of grains  demanded by consumers to be produced by farmers and marketed by traders in the open market. The present study was a national perception survey aimed at establishing the current status of rice grain quality based on the perspectives of traders and consumers interviewed at selected market places in four major cities across the country. In separate interviewsconducted with315 consumers and traders selected at random from 45 markets around the country, individual responses were solicited on the general interests of consumers and traders, as well as the marketing practices and aspirations for the improvement of rice grain quality in the country. Results obtained from the two surveys suggest that the priorities of rice consumers for grain quality were generally similar to those of thetraders. For example, between to 63 to 100 per cent (84 %all cities) of consumers and 69 to 100 percent (88% all cities) of traders interviewed indicated preference for imported rice, with a significant positive correlation (r = 0.78) between the two groups. Among rice products found in the market, the imported high swelling, long grain rice was shown to be preferred by both traders and consumers, due mostly to the high swelling power and non-seasonal market availability of that grain type. Other results suggest that both traders and consumers desire further improvement in grain quality, even though they do not consider this to be of high priority. The study leads to the conclusion that imported rice products are more popular than local rice products among rice traders and consumers in Sierra Leone. It is speculated that such preference might have been driven directly by the priorities of household food decisions and indirectly by the general socio-economics of food production and consumption in the country.Keywords: Rice grain quality, consumers, Sierra Leon

Determination of leaf area index for oil palm plantation using hemispherical photography technique

The present conventional (destructive) method used in determining LAI is laborious, difficult and time consuming. Thus, an image-based measurement using camera system with fish eye lens offers an alternative means for an accurate indirect measurement of LAI in oil palm. In this study, a methodology was developed to improve the leaf area index of the oil palm determination using hemispherical photography as an indirect method. A set of true LAI data, collected using the destructive method, were used as a reference to calibrate the LAI measurements obtained by the hemispherical photography. A good relationship (r = 0.85) was found between age of palm and hemispherical photographic LAI. However, the estimated LAI obtained by the hemispherical photographic method was underestimated as compared to the destructive method. Some means of calibration was necessary to determine the relationship between the actual LAI and the hemispherical photographic LAI. It was necessary to multiply the LAI value from 5 years to 16 years, by a clumping factor of 2.14 for 5 to 9 year old palms, 2.33 for 10 to 14-year old palms and 2.37 for above 15-year old palms to calculate the accurate LAI values. For palms which are less than 5 year old (i.e. 2 to 3 years in this study), the photography LAI value was equal to the calculated LAI value. This proposed that correction factors would solve this underestimation effect. In addition, two equations were also proposed to estimate the true LAI from the Photographic LAI for immature and mature oil palm plantation

A modified soil tilth index and its relationship with rice yield

This study was conducted to investigate the effect of rotary tillage on some soil physical properties (bulk density, cone index, plasticity index, aggregate uniformity coefficient) and organic matter, and to develop and evaluate a soil tilth index based on changes of these soil properties. The tillage treatments were 4×3 factorial combinations of forward speeds obtained with four selected tractor transmission gears (Gear 1 High, Gear 2 Low, Gear 3 Low and Gear 4 Low), and three rotary tilling speeds (140 rpm, 175 rpm and 200 rpm) of commonly used tillage implements in Malaysian paddy fields. Experimental results indicated a significant decrease in bulk density of the soil due to rotary tillage. The other soil parameters were not significantly affected by the tillage operation. Analysis of variance indicated significant difference (p<0.01) among the rice yield means. Bulk density was identified to have a high positive correlation with the rice yield. A tilth index consequently developed with bulk density, cone index and plasticity index gave better predictability (r2= 0.56) of rice yield than when individual soil properties were considered. Results of the study suggest that tilth index may assist in yield prediction by comparing measured soil conditions in a paddy field

Human energy expenditure in lowland rice cultivation in Malaysia

A study was undertaken to evaluate the human energy consumption of various field operations involved in lowland rice cultivation in Malaysia. Based on recorded average heart rates, fertilizing was found to be the most strenuous operation,with an average heart rate of 138 beats min-1. There were no significant differences in the average heart rates of the subjects among the individual tasks within the first plowing, second plowing, and harvesting operations, with the average heart rates for these three tasks being 116, 106, and 106 beats min-1, respectively. The corresponding energy expenditures were 3.90, 3.43, and 3.35 kcal min-1. Loading the seed into the blower tank and broadcasting the seed were the most critical tasks for the seed broadcasting operation, with average heart rates of 124 and 136 beats min-1, respectively. The highest energy expenditure of 418.38 kcal ha-1 was observed for seed broadcasting,and the lowest energy expenditure of 127.96 kcal ha-1 was for second plowing. The total seasonal human energy expenditure for rice cultivation was estimated to be 5810.71 kcal ha-1, 55.7% of which was spent on pesticide spraying. Although the sample size in this study was relatively small, the results indicated that human energy expenditure per unit area (kcal ha-1) was positively linked to the average heart rate of the subjects and negatively linked to the field capacity. Thus, mechanization of certain tasks could decrease worker physical effort and fatigue and increase production

Analysis of energy consumption in lowland rice-based cropping system of Malaysia

Sufficient energy is needed in the right form and at the right time for adequate crop production. One way to optimize energy consumption in agriculture is to determine the efficiency of methods and techniques used. With the current increase in world population, energy consumption needs effective planning. That is, the input elements need to be identified in order to prescribe the most efficient methods for controlling them. This study was undertaken in order to determine the direct and indirect energy consumption of field operations in a lowland rice production system of Malaysia. Field time, fuel and other energy requirements were measured for the tillage, planting, fertilizing, spraying and harvesting operations performed. Energy analysis carried out revealed the highest average operational energy consumption was for tillage (1747.33 MJ ha-1) which accounted for about 48.6% of the total operational energy consumption (3595.87 MJ ha-1), followed by harvesting (1171.44 MJ ha-1, 32.6%) and planting (562.91 MJ ha-1, 15.7%). Fertilizing and pesticide spraying did not make any significant contributions to the operational energy consumption. Based on energy sources, fuel was the main consumer of direct energy with 2717.82 MJha-1 (22.2%), and fertilizer recording the highest indirect energy consumption of 7721.03 MJha-1 (63.2%). Human labour, pesticides, seeds and indirect energy for machinery use had marginal importance, contributing only 0.2%, 0.6%, 6.8% and 6.9%, respectively to the total energy consumption (12225.97 MJha-1). Average grain yield was 6470.8 kg ha-1, representing energy output of 108321.75 MJha-1, that is, 96095.78 MJ net energy gain or 8.86 MJ output per MJ input. Energy input per kilogram grain yield was 1.89 MJkg-1. The results of the study indicate energy gain in the lowland rice production system of Malaysia