Simulation of growth and yield of various irrigated rice (<i>Oryza sativa</i> L.) genotypes by AquaCrop under different seedling ages

Asl

et al. 2022

BFJ

PurposeThis research aims to monitor vegetation indices to assess drought in paddy rice fields in Mazandaran, Iran, and propose the best index to predict rice yield.Design/methodology/approachA three-step methodology is applied. First, the paddy rice fields are mapped by using three satellite-based datasets, namely SRTM DEM, Landsat8 TOA and MYD11A2. Second, the maps of indices are extracted using MODIS. And finally, the trend of indices over rice-growing seasons is extracted and compared with the rice yield data.FindingsRice paddies maps and vegetation indices maps are provided. Vegetation Health Index (VHI) combining average Temperature Condition Index (TCI) and minimum Vegetation Condition Index (VCI), and also VHI combining TCImin and VCImin are found to be the most proper indices to predict rice yield.Practical implicationsThe results serve as a guideline for policy-makers and practitioners in the agro-food industry to (1) support sustainable agriculture and food safety in terms of rice production; (2) help balance the supply and demand sides of the rice market and move towards SDG2; (3) use yield prediction in the rice supply chain management, pricing and trade flows management; and (4) assess drought risk in index-based insurances.Originality/valueThis study, as one of the first research assessing and mapping vegetation indices for rice paddies in northern Iran, particularly contributes to (1) extracting the map of paddy rice fields in Mazandaran Province by using satellite-based data on cloud-computing technology in the Google Earth Engine platform; (2) providing the map of VCI and TCI for the period 2010–2019 based on MODIS data and (3) specifying the best index to describe rice yield through proposing different calculation methods for VHI.

Section: Monitoring Vegetation Indices 4219mentioning

confidence: 99%

“…Rice has a significant share in the Iranian diet based on the nutritional and world rice trade (Kalantari et al. , 2020), which is ranked second in the Iranian food basket in terms of consumption with approximately 38–42 kg per capita (Seyed Raoufi et al. , 2018).…”

Section: Introductionmentioning

confidence: 99%

Drought assessment in paddy rice fields using remote sensing technology towards achieving food security and SDG2

Asl

et al. 2022

BFJ

“…Therefore, the output of this model mainly includes the following four parts: canopy coverdevelopment, biomass accumulation and soil moisture content changes during the crop growth period, and final rice yield. The core idea of the AquaCrop model is the D-K model proposed by Doorernbos and Kassam in 1979 [29]. On this basis, the AquaCrop model distinguishes soil evaporation from crop transpiration by the canopy coverage and then calculates the aboveground biomass by transpiration and normalized water production efficiency and controls the final yield by the harvest index.…”

Section: Aquacrop Model and Parametersmentioning

confidence: 99%

Rice Irrigation Schedule Optimization Based on the AquaCrop Model: Study of the Longtouqiao Irrigation District

Zhai

et al. 2019

Water

As a crop with high water consumption, rice is an important measure of efforts to improve agricultural irrigation efficiency and alleviate the contradiction between the supply and demand of agricultural water resources. This paper takes the Longtouqiao irrigation district, in the hinterland of the Sanjiang Plain, a major rice-producing area in northern China, as an example, and the AquaCrop crop growth model and entropy-cloud model are jointly used to develop a rice irrigation schedule optimization model based on three kinds of typical rainfall years. Different irrigation schemes are established and evaluated by using the model built based on images. The results showed that the yield's normalized root mean square error (NRMSE) value of the AquaCrop model was 9.949% (< 10%) after calibration, and the our model results showed a good agreement with observed data, which indicated that the calibrated model was suitable for rice growth simulation in the research area. For the same irrigation water amount, rice was irrigated to a great extent at the tillering stage, and a small amount of irrigation water at the regreening stage of rice could improve rice yield. During irrigation, rice production can also be promoted by regulating the irrigation amount according to the rainfall in each growth period, and the optimal irrigation water amount can be controlled between 20 and 60 mm each time. Under the three typical annual scenarios of dry, normal and wet years, the respective optimal quantification results for the field capacity, total irrigation water amount and irrigation times in the rice growth period to attain the optimal irrigation effect were 25%, 425 mm, and 17 times, respectively; 25%, 450 mm, and 14 times; respectively, and 25%, 425 mm, and 17 times, respectively. The research results can provide a decision-making basis for water-saving measures and efficient rice irrigation water management.

Water Resources Research

“…Among rice planting methods, hand seedling transplanting, that is, traditional transplanting, is the preferred method in Iran (Seyed Raoufi et al., 2018) due to the required lower seed per hectare and the easier weed control, but more intensive human labor is needed (Dendup & Chhogyel, 2018). In recent decades, mechanical transplanting has been increasingly replacing the traditional transplanting method in rice production to reduce human labor and labor costs; also, the ease of cultivation and the higher yield stability can enhance the household incomes (Hou et al., 2019; Knight et al., 2011; Liu et al., 2015).…”

Section: Introductionmentioning

confidence: 99%

Effects of Water Source and Technology on Energy Use and Environmental Impacts of Rice Production in Northern Iran

Jamali

Bakhshandeh

Emadi

2022

To assess the sustainability of rice production systems, it is essential to quantify its impact on the environment and energy flow. To analyze the energy flow and greenhouse gas emissions, a total of 200 paddy fields were selected based on the water source utilized for irrigation (river as the surface water source and well as the underground water source), transplanting methods (traditional and mechanical) and grain yield (low‐ and high‐yielding rice cultivars) based on a factorial experimental design (2 × 2 × 2 = 8 conditions). Data were collected in 2020 from 200 rice growers in northern Iran, using a face‐to‐face questionnaire survey. Results showed that the highest total energy use efficiency (EUE) (5.26 GJ ha−1) was observed under the surface water source + traditional + low‐yielding rice system. Although the total EUE in surface water source was higher than that in groundwater source (4.98 vs. 2.90). Water consumption by high‐yielding rice cultivars was higher, as compared to the low‐yielding ones. Electricity (35.2%) and nitrogen fertilizer (31.5%) inputs were the highest energy input for the groundwater and surface water sources, respectively. Average shares of the renewable and non‐renewable energies used in agroecosystems were 25.70% and 74.30% respectively, while the shares of the direct and indirect energies were 60.36% and 39.64%, respectively. The calculated global warming potential value in the paddy fields of northern Iran ranged from 878 to 2,666 kg eqCO2 ha−1. Amongst the studied conditions, the surface water source + traditional + high‐yielding rice system had the highest carbon efficiency and carbon sustainability index level. Overall, surface water source conditions were found to be a more environmentally‐friendly approach in northern Iran. These results, thus, demonstrated that there is a huge potential for improving energy efficiency in the studied conditions, especially for high‐yielding rice cultivars irrigated by surface water sources. These findings could help decision‐makers to better understand the linkage between various conditions, which is a prerequisite to any planning effort for future management strategies at national and international levels.