An assessment of irrigated rice production energy efficiency and environmental footprint with in-field and off-field rice straw management practices

Abstract

The research provided scientific evidences for improved rice straw management. Rice cultivation with in-field burning of rice straw is the worst option with the lowest energy efficiency and highest air pollution emission. This article comprises a comparative assessment of energy efficiency and the environmental footprint of rice production using four different rice straw management scenarios, namely, straw retained, straw burned, partial straw removal, and complete straw removal. Paddy yield, grain quality, and energy balance were assessed for two seasons while greenhouse gas emissions (GHGE) were measured weekly starting from land preparation through to the cropping and fallow period. Despite the added energy requirements in straw collection and transport, the use of collected rice straw for mushroom production can increase the net energy obtained from rice production systems by 10–15% compared to burning straw in the field. Partial and complete removal of rice straw reduces GHGE by 30% and 40% compared to complete straw retention, respectively.

Assessment of post-harvest losses and carbon footprint in intensive lowland rice production in Myanmar

“…Energy value (EV) of rice product 36 is 15.2 MJ kg −1 while that of rice bran, broken rice, and discolored rice is 9.6 MJ kg −1 (Econivent 3 database 19 ) with an assumption that these by-products are used for cattle feed and have a similar economic value. EV of rice husk is 8.7 MJ kg −1 (Ecoinvent 3 database 19 ) and straw is 3.5 MJ kg −1 20 based on an asumption that partially harvested straw were collected for mushroom production. The collected amount of rice straw was about 50% of the grain yield at harvest 34 .…”

“…The economic and technical efficiency of post-harvest systems in rice production have been quantified in Korea 14 , Bangladesh 15 , Pakistan 16 , Thailand 17 , Myanmar 4 , and Vietnam 18 . Quantification of energy efficiency and GHGE of rice production using a life cycle assessment (LCA) approach has been reported in a global database 19 and in specific studies in different countries such as the Philippines 20 , Japan 21 , Iran 22 , Italy 23 , and Canada 24 . Post-harvest losses and mechanization also have been investigated for specific processes such as farm mechanization 25 , drying 6 , and mechanized rice straw collection 26 .…”

An assessment of irrigated rice cultivation with different crop establishment practices in Vietnam

“…Energy efficiency, which is the net energy difference between outputs and inputs of rice production, could vary depending on many factors including site-specific management of water, nutrients, pests and crop residues. Previous studies report a wide range for the estimate of net energy value for irrigated rice: 13.7 MJ kg -1 rice produced in Ecoinvent (2019) 34 ; 11.3–12.3 MJ kg −1 for rice in the Philippines in Quilty et al (2014) 45 ; and 10–28 MJ kg −1 for production in the Philippines with different rice straw management practices 36 . The estimates of total input energy of rice production in the current study are similar to those reported for irrigated rice production in Southeast Asian 36 , 45 , 52 .…”

“…Previous studies report a wide range for the estimate of net energy value for irrigated rice: 13.7 MJ kg -1 rice produced in Ecoinvent (2019) 34 ; 11.3–12.3 MJ kg −1 for rice in the Philippines in Quilty et al (2014) 45 ; and 10–28 MJ kg −1 for production in the Philippines with different rice straw management practices 36 . The estimates of total input energy of rice production in the current study are similar to those reported for irrigated rice production in Southeast Asian 36 , 45 , 52 . The energy efficiency value in the current study (11–14 MJ kg -1 ) was similar with that reported in Ecoinvent (2019) 34 and was higher by 10% than that reported in Quilty et al (2014) 45 , which is likely because of higher grain yield in the MRD compared to that produced in the Philippines.…”

Crop Rotation Enhances Agricultural Sustainability: From an Empirical Evaluation of Eco-Economic Benefits in Rice Production

“…If nutrient residues from the preceding crops are high, the application of fertilizer and other forms of nutrient should be reduced in succeeding production, and vice versa [51,53]. Together with an appropriate water management strategy, this consideration can reduce ineffective tillers and straw biomass, leading to both improved harvest index and grain yields [54]. The organic matter and mineral element levels in the PR soil were significantly higher than in the other cropping systems (Table 3), suggesting that more nutrient residues are retained in the rotation fields with PR in particular.…”