Upland Crops Research Articles

Effects of no-till on upland crop yield and soil organic carbon: a global meta-analysis

Effects of no-till on upland crop yield and soil organic carbon: a global meta-analysis

Bio-straw resource recycling systems: Agricultural productivity and green development

Bio-straw is one of the valuable and renewable organic resources. China produces most of the world's bio-straw. Straw recycling is closely associated with global carbon and nitrogen cycles, agricultural productivity, and green development. We systematically integrated straw recycling systems from 1979 to 2019 into three major cereal crops to identify patterns of crop productivity and greenhouse gas (GHG) emissions in a life cycle assessment, and to explore GHG mitigation potential using scenario analyses. Straw recycling partially alleviated the negative potassium surplus caused by straw removal and increased wheat, maize, and rice yields by 7.8%, 5.2%, and 5.0%, respectively. We developed a new empirical model for nitrous oxide (N2O) and methane (CH4) emissions from straw recycling systems in regional crops. Straw recycling promoted direct N2O emissions from upland crops, especially maize. Nonetheless, straw recycling reduced net GHG emissions by 33.1% in wheat and 12.1% in maize due to high rates of soil carbon sequestration relative to inorganic fertilizer management alone. In rice, straw recycling depressed N2O emissions but increased net GHG emissions by 59.8% because CH4 emissions were 2.06 times greater than those under fertilizer management. When combined with optimal fertilizer inputs based on zero nutrient surplus, 100% straw recycling further reduced net GHG emissions by 28.0% in wheat and 19.5% in maize, whereas 60% straw recycling produced better results in rice (20.6% emissions reduction), in spite of increasing fertilizer-induced emissions. Enhancing the quantity and quality of straw recycling, based on crop-specific recycling targets, should contribute to the dual targets of achieving higher crop yields and green development.

Heavy metals in agricultural soil in China: A systematic review and meta-analysis

Research about farmland pollution by heavy metals/metalloids in China has drawn growing attention. However, there was rare information on spatiotemporal evolution and pollution levels of heavy metals in the major grain-producing areas. We extracted and examined data from 276 publications between 2010 and 2021 covering five major grain-producing regions in China from 2010 to 2021. Spatiotemporal evolution characteristics of main heavy metals/metalloids was obtained by meta-analysis. In addition, subgroup analyses were carried out to study preliminary correlations related to accumulation of the pollutants. Cadmium (Cd) was found to be the most prevailing pollutant in the regions in terms of both spatial distribution and temporal accumulation. The Huang-Huai-Hai Plain was the most severely polluted. Accumulation of Cd, mercury (Hg) and copper (Cu) increased from 2010 to 2015 when compared with the 1990 background data. Further, the levels of five key heavy metals (Cd, Cu, Hg, lead [Pb] and zinc [Zn]) showed increasing trends from 2016 to 2021 in all five regions. Soil pH and mean annual precipitation had variable influences on heavy metal accumulation. Alkaline soil and areas with less rainfall faced higher pollution levels. Farmlands cropped with mixed species showed smaller effect sizes of heavy metals than those with single upland crop, suggesting that mixed farmland use patterns could alleviate the levels of heavy metals in soil. Of various soil remediation efforts, farmland projects only held a small market share. The findings are important to support the research of risk assessment, regulatory development, pollution prevention, fund allocation and remediation actions.

Nitric Oxide Emissions from Chinese Upland Cropping Systems and Mitigation Strategies: A Meta-analysis

Agroecosystems are a significant source of nitric oxide (NO), a potent atmospheric pollutant. It has been well documented that the NO emissions from upland cropping systems and their emission factors are large relative to those from paddy fields. However, a clear understanding of their uncertainty and regulating factors is still lacking. To date, various field experiments have been conducted to investigate NO emissions and mitigation, providing an opportunity for a Meta-analysis. The aims of this study were to 1 investigate the uncertainty and regulating factors of NO emissions and emission factors from maize-winter wheat rotations, non-waterlogging period in rice-winter wheat rotations, vegetable fields, tea plantations, and fruit orchards across China by extracting data from peer-reviewed publications, and 2 quantify the mitigation potential of management practices, such as reducing nitrogen fertilizer input, organic substitution with chemical fertilizers, and application of enhanced-efficiency nitrogen fertilizers or biochar by performing a pairwise Meta-analysis. A total of 49 references (published from 2006 to 2021) were collected. The results showed that annual NO emissions from the maize-winter wheat rotations, tea plantations, and fruit orchards averaged 1.44, 7.45, and 0.92 kg·hm-2, respectively, with significant differences among the three cropping systems (P<0.05). The seasonal NO emissions from the non-waterlogging period in rice-winter wheat rotations and vegetable fields within a single growth period averaged 2.13 kg·hm-2 and 2.09 kg·hm-2, respectively. The NO emissions positively related to nitrogen inputs in the maize-winter wheat rotations, non-waterlogging period in rice-winter wheat rotations, and tea plantations (P<0.01) but not in the vegetable fields and fruit orchards. The emission factors averaged 0.31%, 0.71%, 0.96%, 1.74%, and 0.13% in the maize-winter wheat rotations, non-waterlogging period in rice-winter wheat rotations, vegetable fields, tea plantations, and fruit orchards, respectively, with significant differences among the cropping systems (P<0.01), except between the maize-winter wheat rotations and non-waterlogging period in rice-winter wheat rotations or vegetable fields (P>0.05). Considering the substantial differences in emission factors among the cropping systems, a specific emission factor for each system should be applied when estimating an agricultural NO budget at a regional or national scale. Reducing nitrogen input only mitigated NO emissions (by 36%) at a reducing nitrogen ratio above 25% but did not impact emission factors. An optimal reducing nitrogen ratio has to be further evaluated without crop productivity penalties. Organic substitution in soils with organic carbon content<15 g·kg-1 or pH<7 and application of enhanced-efficiency fertilizers in the maize-winter wheat rotation simultaneously mitigated NO emissions (by -46%- -38%) and emission factors (by -62%- -45%). By contrast, biochar amendment had no significant effects on either NO emissions or emission factors. These findings highlight a possibility of choosing an effective NO mitigation strategy under specific field conditions.

Projected changes in field workability of agricultural machinery operations for upland crop production with +4 K warming in Hokkaido, Japan

Projected changes in field workability of agricultural machinery operations for upland crop production with +4 K warming in Hokkaido, Japan

Analysis of enzyme activity changes caused by flooding stress in upland crops

Analysis of enzyme activity changes caused by flooding stress in upland crops

Development of Drought Vulnerability Index for Upland Crops using Soil Moisture Data

Recently, with changing rainfall patterns worldwide due to climate change, the effects and damages of upland crops are increasing. A water supply system from irrigation facilities such as agricultural reservoirs and pumping stations has been established in paddy fields, whereas irrigation uplands equipped with water supply facilities account for only 18.5% of the upland area. Therefore, it is necessary to analyze vulnerable areas of upland droughts because they depend on natural rainfall and lack the ability to respond to drought damage. Currently, there is limited drought information to respond to an upland drought because the characteristics of crops and actual cultivation period are not analyzed. Soil moisture directly resulting from rainfall shortage is highly related to drought, especially for upland crops and vegetation. Therefore, upland crops drought can be evaluated using soil moisture and weather data. In this study, an upland drought vulnerability index based on runs theory and entropy method was developed using effective soil moisture, soil moisture drought index, and groundwater level. Soil moisture and meteorological data were obtained from the soil moisture observation network (Rural Development Administration), and weather observation network (Korea Meteorological Administration). The results showed that Upland Drought Vulnerability Index (UDVI) can be an effective tool for quantitatively evaluating upland drought vulnerability.

Root pruning is effective in alleviating the inhibition of soybean growth caused by anaerobic stress for a short period

Soybean is an important upland crop, but its productivity is often limited by anaerobic stress caused by waterlogging. The ability to adjust root growth under environmental constraints is an important physiological trait for adapting to an ever-changing environment, and root pruning is an artificial technique for regenerating the root system. In the present study, we investigated whether root pruning in soybean can effectively alleviate the inhibitory effects of anaerobic stress. Soybean plants were affected by anaerobic stress at the germination, vegetative stage 1 (V1), and reproductive stage 1 (R1) stages, and then the plants were treated with root pruning just after the stress treatment. Soybean plants at the germination stage were treated with root cap and tip removals after hypoxia (N2 treatment). Root cap removal was more effective in suppressing the inhibitory effects of hypoxia than root tip removal (5 mm from the tip). The shoot dry weights of the soybean plants with and without root cap removal after hypoxia were 51.2 and 73.8% of the control, respectively, while the root dry weights of plants with and without root cap removal after hypoxia were 43.2 and 62.8% of the control, respectively. As root cap removal effectively enhanced soybean growth after anaerobic stress, the root cap may be the candidate tissue for the stress memory mechanism. When soybean plants at the V1 stage of growth were affected by anaerobic stress, the branch number, pod weight in the main stem, root length, and root surface area of the soybean plants treated with anaerobic stress at the R1 stage significantly decreased compared with those of the control. In contrast, root pruning (2 mm from the tip) immediately after the stress treatment enhanced root growth, branch number, and pod weight. The branch number, pod weight, root length, and root surface area of the plants treated with root pruning were 1.13, 1.14, 1.12, and 1.13 times higher than those of plants treated with anaerobic stress. Plasmolysis was observed in the root meristem, columella, and cortical cells in soybean roots subjected to anaerobic conditions. However, damage was not observed in the newly emerged roots after root pruning in plants treated with anaerobic stress. These results suggested that root pruning is effective in enhancing soybean growth after anaerobic stress. This effectiveness may be due to the regeneration and elongation of healthy lateral roots during the recovery period. When soybean plants were affected by anaerobic stress at the R1 stage, root pruning just after the stress treatment was ineffective. Thus, suppressing the growth reduction due to anaerobic stress at reproductive stages using only root pruning may be difficult.

Effects of land use type and tank components on soil properties and sustainability of tank cascade system in the Dry Zone of north central Sri Lanka

CONTEXTVillage tank cascade system (VTCS) is a globally important agricultural heritage system in Dry Zone watersheds of Sri Lanka. Lands in these watersheds have been under changing management conditions in the recent past, hence their sustainability has been suspected. OBJECTIVEObjectives of this study were to determine current status of soil properties in different land uses and tank components of a VTCS with respect to their position in the watershed, and to assess sustainability of this agricultural system using soil organic carbon management index (CMI) as a proxy. METHODSStudy was conducted in Mahakanumulla VTCS in North Central Dry Zone of Sri Lanka. Soil samples (n = 120) were collected from lands under forest, scrub/shrub, paddy and upland crops representing all elevations in two linear transects located in higher and lower positions along the main valley. Soils from components of tanks in upper and lower positions were also collected. Soil texture and some chemical properties were measured. The CMI in different land uses was calculated using total organic carbon (TOC) and permanganate oxidizable carbon contents. RESULTS AND CONCLUSIONSEffect of land use type on soil properties did not vary with position in the watershed (p > 0.05). An increase in available phosphorus and sulphur was observed in agricultural lands. Significant decreases in TOC (33%) and total N (43%) contents were observed in paddy lands compared to those of forest lands (p < 0.01). However, CMI indicated that management practices in paddy lands and upland soils are still sustainable but scrub/shrub lands need improvements to arrest their degradation. Electrical conductivity, pH, available P, K and Zn were significantly higher in lower positions while total N was lower. Thaulla (inundation area) and Perahana (filter) tank components had regulated flow of clay particles while Kattakaduwa (interceptor) has significantly high available P and TOC contents due to high wetness. Principal component analysis revealed factors that control soil erosion, soil organic matter content, water movement, cation availability and P dynamics governed the variability of major soil properties. Accumulation of soluble salts in lands of lower positions and increase of available plant nutrients in agricultural lands suggest that management practices so far adopted have slightly degraded soil fertility in this VTCS. SIGNIFICANCEFurther degradation of soils in lower positions and scrub/shrub lands in the watershed will negatively affect the livelihood of villagers and the environment. Hence, appropriate land management policies should be introduced to this agricultural system to ensure their sustainability.

Spatiotemporal Heterogeneity Monitoring of Cropland Evolution and Its Impact on Grain Production Changes in the Southern Sanjiang Plain of Northeast China

High-speed cropland changes are taking place in Northeast China, bringing about the sustainable changes in ecological landscape and food production; however, the lack of continuous research limits the revelation of new findings in this region. The integrated approach of land migration tracking, ecological landscape and mathematical statistics was established to conduct a comprehensive survey of land change–landscape–food security in a typical grain-planting region of Northeast China to reveal new changes from 1990 to 2020. Results display that the cropland area continued to increase from 25,885.16 km2 in 1990 to 31,144.46 km2 in 2020, leading to the loss of forest land, grassland, water body and unused land. For cropland structure, the proportion of paddy fields in cropland increased rapidly from 7.18 to 39.53% during 1990–2020; in contrast, upland crops decreased sharply. The richness of landscape presented gradually complex characteristics with SHDI from 0.258 to 0.671 and other ecological indicators underwent similar changes with strong regularity. Total grain production displayed a continuous increase, with values from 523.79 × 104 t to 1839.12 × 104 t, increasing by 2.51 times from 1990 to 2020. We also revealed the contribution rate of unchanged upland crops to grain increments was the largest (i.e., 46.29%), and the conversion of internal cropland structure (i.e., the paddy fields converted from upland crops) contributed 12.17% from 1990 to 2020, showing a positive signal for food security. These new findings provide studies on land use change, ecological landscape and food security in China and abroad.

Critical reevaluation of an efficient sampling design for assessing soil properties using bootstrap sampling and geostatistical analysis in Japanese large-scale paddy fields

ABSTRACT Soil test is a key step toward providing recommendations for better crop management. Several soil samples have been traditionally assumed to be sufficient for soil tests to represent field-specific values in conventional Japanese small-scale paddy fields. However, rethinking soil sampling design is required, as many small-scale (<0.3 ha) paddy fields have been consolidated into large-scale (>1 ha) paddy fields to enhance the efficiency of crop production. The purpose of this study is to explore an efficient soil sampling design, including sample size for representing field-specific values and sampling distance for representing spatial variations, in central Japan using bootstrap sampling and geostatistical analysis. Fourteen soil properties were quantified from 553 samples, which was collected at a distance of 24.4 m on average in large-scale paddy fields with continuous rice cultivation and rotation of rice and upland crops (winter wheat and soybean). The results show that the conventional sampling size (n = 3 for each field) achieved mean estimation within 10% error with 95% confidence intervals only for pH and sand content in almost all fields; thus, an optimization of field-specific uniform liming rate is recommended for reducing cost. Geostatistical analysis shows that the recommended soil sampling distance should be 15–163 m, depending on specific soil properties. The results further show that it was difficult to obtain reliable estimates of exchangeable K and mineralizable N because of the high level of spatial uncertainty with high nugget variance. Thus, practitioners should note that the outcomes from soil tests inherently included fine-scale errors in available nutrient levels which may preclude rationale prescriptions. This study demonstrated that appropriate soil sampling design and the subsequent soil management can differ depending on specific soil properties in the actual farming scale of large-scale paddy fields.

Evaluation of Pedotransfer Functions for Estimating Soil Water Retention Curve of Ap Horizon Soils for Various Soil Series of Reclaimed Tidal Flat Soil

This investigation was to evaluate the applicability and prediction accuracy of pedotransfer function (PTF) to estimate the water retention curves of Ap horizon soils for five soil series which cannot be directly used to cultivate upland crops other than rice because of their high salinity. Soil water retention curves (SWRCs) were obtained from 150 undisturbed soil samples collected from the Ap horizons of which soil textures were grouped into sandy loam with high contents of sand (&gt;60%) and low clay contents (&lt;10%) and silt loam with relatively high silt content (&gt;60%) and low sand content (&lt;10%). Soil-water retention characteristics between 0 to −50 kPa and −50 to −1500 kPa were measured using the sandbox, kaolin-plate, and pressure chamber methods, respectively. The SWRCs were also estimated by Rawls and Brakensiek PTF (RB-PTF). The measured SWRCs of sandy loam and silt loam were compared against those obtained from RB-PTF. The SWRCs estimated with the modeled data closely fit the measured data of sandy loam and silt loam although saturated volume water content (θs) and residual volume water content (θr) of RB-PTF were higher than those of the measured mean for both soil textures. The air entry point (α) and the steepness of the water-retention curve (n) were higher in sandy loam than those of silt loam. SWRCS estimated by the RB-PTF yielded the best fit of all soil samples from the five series, whereas the MBE values less than zero indicate that θv measured at the water potentials is under-predicted. The r2 values greater than 0.9 for sandy loam and silt loam represent RB-PTF and are suitable for predicting SWRCs in RTFS because the measured data points do not vary around the estimated regression line.

Methane emission, methanogenic and methanotrophic communities during rice-growing seasons differ in diversified rice rotation systems

Appropriate crop rotation in rice field is an important measure to maintain soil fertility and rice productivity. However, the effects of different rice rotation systems on methane (CH4) emission and the underlying mechanisms, as well as rice grain yields have not been well assessed. Here, a 2-year field study involving three rice rotation systems (Wh-PR: wheat-flooded rice rotation, Ra-PR: rapeseed-flooded rice rotation, Ra-UR: rapeseed-aerobic rice rotation) was conducted. CH4 emissions, methanogenic and methanotrophic communities and rice grain yields were measured during rice growing seasons to determine which rice rotation pattern can reduce CH4 emissions and improve rice grain yields. The average cumulative CH4 emission was 136.19 kg C ha−1 in Ra-PR system, which was significantly higher than that in Wh-PR and Ra-UR systems by 60.6 % and 14.6-fold, respectively. These results were mainly attributed to the low soil dissolved organic carbon in Wh-PR system and the well aerated soil condition in Ra-UR system, as compared with Ra-PR system. Rice grain yields exhibited no significant differences among the three rotation systems in 2019 and 2020. The abundances of methanogens in Ra-PR system were obviously higher than those in Wh-PR and Ra-UR systems. While the abundances of methanotrophs were comparable between Ra-PR and Wh-PR systems, which exhibited significantly lower abundances than that in Ra-UR system. CH4 fluxes showed markedly positive relations to the abundances of methanogens, while exhibited no relationship with the abundances of methanotrophs. Both methanogenic and methanotrophic community compositions differed considerably in Wh-PR and Ra-UR systems in comparison with Ra-PR system. Specifically, the relative low abundances of Methanothrix and Type I methanotrophs occurred in Wh-PR and Ra-UR systems, whereas Methanosarcina, Methanocella, Methanomassiliicoccus and type II methanotrophs (Methylocystis and Methylosinus) were found in higher relative abundances in Wh-PR and Ra-UR systems. Overall, changing the preceding upland crop types or introducing aerobic rice to substitute flooded rice in rice-based rotation systems could diminish CH4 emissions, mainly by regulating soil properties and eventually changing soil methanogenic and methanotrophic communities.

Empirical Setting of the Water Stressed Baseline Increases the Uncertainty of the Crop Water Stress Index in a Humid Temperate Climate in Different Water Regimes

Water productivity of rice is imperative for global water security. Currently, water saving management techniques have been proposed and applied to rice systems. The crop water stress index (CWSI) is a major index for evaluating crop water use. The utility of the CWSI in rice in a humid temperate climate has been given little attention. Previous studies have focused on upland crops and readily available constant reference baselines, primarily the water stressed baseline (WSB), which does not inherently reflect transpiration flux. This study examined the performance of the estimated non-water stressed baseline (NWSB) and WSB for rice in a humid climate and the CWSI sensitivity under variable reference baseline scenarios in a 2-year pot trial under phytotron and field environment conditions with two rice genotypes (IRAT109 and Takanari) in a flooded (FL) and aerobic (AR) water regime. We observed that the dynamics of CWSI is dependent not only on the water regimes but could be strongly influenced by genotype sensitivity to vapor pressure deficit (VPD). A higher slope (pooled data) in the field environment (−5.68 °C kPa−1) compared to the phytotron (−3.04 °C kPa−1) reflected transpiration water loss sensitivity to VPD thresholds. Further studies with diverse rice germplasms to explore generalizability to field conditions and reformulation of reference baselines considering the VPD threshold sensitivity could prove to be significant.

Development of Low-cost Soil Moisture Monitoring System for Efficient Irrigation Water Management of Upland Crops

With the advancement of information and communication technology, various types of soil moisture sensors have been developed. Coupled with data loggers, these sensors could prove useful in monitoring soil moisture in upland crop production areas which in turn could be used for efficient irrigation water management. However, most of these sensors are costly and unaffordable to most farmers in developing countries. Hence, a low-cost soil moisture monitoring system intended to facilitate irrigation water management in upland crop production systems was developed in this study. The device was built with a capacitive soil moisture sensor, an ESP8266 Wi-Fi mini board, and a datalogging shield with RTC. Soil moisture measurements are transmitted via ESP-NOW to a server which also uses an ESP8266 Wi-Fi mini board. The low-cost soil moisture monitoring system was evaluated based on its measurement of volumetric water content and transmission of data via ESP-NOW. The performance of the capacitive soil moisture sensor was compared with the ICT International MP306 soil moisture sensor. Statistical analyses showed that volumetric water contents measured by the capacitive soil moisture sensor are comparable to those of the MP306 soil moisture sensor, thus conceived as a low-cost alternative to the high-end sensor. Moreover, test results on the range of ESP-NOW showed that data can be successfully transmitted over long distances. With regards to this, the low-cost soil moisture monitoring system may be integrated with other technologies to enable irrigation scheduling and automation for efficient irrigation water management in upland crop production systems.

Hydraulic Performance Evaluation of Low-Cost Gravity-Fed Drip Irrigation Systems Under Constant Head Conditions

The use of drip irrigation for upland crop production has gained popularity in developing countries due to its relatively high water-use efficiency. To maximize the efficiency of this irrigation method, it is important to evaluate its hydraulic performance in terms of emitter discharge and water distribution uniformity under various operating heads. In this study, the hydraulic performance of two locally available low-cost drip irrigation kits -referred to in this study as Drip Kit A and Drip Kit B - was assessed and compared under constant head conditions. Both drip kits are composed of a 1000-L intermediate bulk container (IBC) tank, 10-m submain line, 20-m lateral lines spaced 0.75 m apart, and cascade labyrinth emitters spaced 0.30 m apart along the laterals. Operating heads of 2.5, 3.5, 4.0, 4.5, 5.0, 5.5 m were used and maintained throughout the trials with the use of an overflowing tank. The submain and lateral lines were levelled (0% slope). Sampling of discharge rates was done for one-third of the total number of emitters for each of the tests performed. Results showed that the overall system emitter discharge rate generally increases with increasing operating head. Moreover, emitters farther from the submain line generated relatively lower discharge rates than those closer to it. Analysis of the experimental data showed that the Christiansen’s coefficient of uniformity (CU), emission uniformity (EU), and coefficient of variation (CV) ranged from 97.5 to 98.5, 95.9 to 97.7, and 0.02 to 0.04 for the drip systems tested. Further statistical analysis also showed that varying the operating heads does not have a statistically significant effect (α=5%) on the CU, EU, and CV of the system. Based on the results, Drip Kit B performed better than Drip Kit A in terms of water distribution uniformity. However, the latter could generate higher emitter discharge rates than the former. For both drip kits, an operating head of 2.5-m is recommendable for a 200 m2 plot, from the practical standpoint. This study has generated important empirical data that could serve as a basis for maximizing the performance efficiency of locally available drip irrigation systems for a more efficient irrigation water management.

Development of a real-time wireless sensor network-based information system for efficient irrigation of upland and lowland crop production systems

This study developed a real-time web-and WSN-based information system for efficient irrigation water management and automation of drip-irrigated upland crop and intermittently-irrigated lowland crop production systems. The web-based system uses Flutter and DART to accommodate multiple end user platforms, while the WSN-based system uses state-of-the-art hardware and sensors for real-time monitoring of soil moisture, water level and weather conditions. The sensors are wirelessly connected in a low-power mesh network that sends data to a central server. The sensor readings are uploaded to the web application via MQTT, which generates charts and graphs for data analysis. The sensor readings compared well with measurements from conventional instruments. The system in this study provides a sustainable solution for improving irrigation efficiencies under both upland and lowland crop production systems, in minimizing water losses and in improving the overall agricultural crop productivity.

Development of mobile application for wireless sensor networks for efficient irrigation water management

The evolution of smart phones has necessitated the development of mobile applications designed to perform a wide variety of functions. In the field of agriculture, mobile applications are currently used to monitor environmental parameters such as ambient temperature, humidity, soil moisture, water level, among others. A mobile application intended to monitor irrigation-related parameters and to control solenoid valves for irrigation automation was developed in this study. The mobile application was written using Flutter software development kit, and the Dart programming language. The mobile application communicates with the cloud server using a REST API written in JavaScript. The data acquired from the cloud server are presented as the current sensor reading and graphs. On the other hand, the mobile application controls the solenoid valves by sending designated bytes of data to the cloud server. The mobile application developed in this study was designed to be integrated with both low-cost sensors and the Smartmesh IP sensors to enable real-time monitoring and data visualization, and facilitate irrigation scheduling and manual irrigation control. The mobile application developed in this study may be used for efficient irrigation water management of upland crop production systems and for agricultural modernization in the Philippines and other developing countries.

Factors Affecting the Agricultural Restructuration: A Case of Cham Community in Chau Phu District, An Giang Province, Vietnam

The national policy of agricultural restructuring plays a vital role in adapting to climate change's effects and economic development in the Mekong Delta of Vietnam. Unproductive areas have been converted into other crops with higher efficiency. Drawn by the sustainable livelihoods approach, this article explores the current situation and factors challenging the Cham community in implementing the agricultural restructuring. The mixed method included in-depth interviews, focus group discussions, and a questionnaire survey. The results showed that the Xuong Com Vang longan (Dimocarpus longan) variety has occurred in Khanh Hoa commune for a long time as an indigenous fruit tree of this area. In terms of the farming system, the polyculture system combining fruit trees and upland crops brought more income sources than the monoculture system. The asset abilities of the Cham farmers are various from one to the others. Soil and weather conditions are appropriate for planting. But farm size is small, which is one of the difficulties of developing fruit areas. Human and social assets were good since farmers had enough knowledge to manage the gardens, and a close connection existed among the Cham community. It was not a case of the financial status since a lot of money needs to be invested in the starting year. Therefore, the private loan still exists as one of the farmer's choices. For better future development, land management and financial resource should be considered for better agricultural restructuring aims. To increase farmers' incomes, create production chains helping enterprises and farmers work more efficiently for the better life of Cham gardeners in An Giang province in Vietnam.

Combined morpho-physiological, ionomic and transcriptomic analyses reveal adaptive responses of allohexaploid wheat (Triticum aestivum L.) to iron deficiency

BackgroundPlants worldwide are often stressed by low Fe availability around the world, especially in aerobic soils. Therefore, the plant growth, seed yield, and quality of crop species are severely inhibited under Fe deficiency. Fe metabolism in plants is controlled by a series of complex transport, storage, and regulatory mechanisms in cells. Allohexaploid wheat (Triticum aestivum L.) is a staple upland crop species that is highly sensitive to low Fe stresses. Although some studies have been previously conducted on the responses of wheat plants to Fe deficiency, the key mechanisms underlying adaptive responses are still unclear in wheat due to its large and complex genome.ResultsTransmission electron microscopy showed that the chloroplast structure was severely damaged under Fe deficiency. Paraffin sectioning revealed that the division rates of meristematic cells were reduced, and the sizes of elongated cells were diminished. ICP-MS-assisted ionmics analysis showed that low-Fe stress significantly limited the absorption of nutrients, including N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, and B nutrients. High-throughput transcriptome sequencing identified 378 and 2,619 genome-wide differentially expressed genes (DEGs) were identified in the shoots and roots between high-Fe and low-Fe conditions, respectively. These DEGs were mainly involved in the Fe chelator biosynthesis, ion transport, photosynthesis, amino acid metabolism, and protein synthesis. Gene coexpression network diagrams indicated that TaIRT1b-4A, TaNAS2-6D, TaNAS1a-6A, TaNAS1-6B, and TaNAAT1b-1D might function as key regulators in the adaptive responses of wheat plants to Fe deficiency.ConclusionsThese results might help us fully understand the morpho-physiological and molecular responses of wheat plants to low-Fe stress, and provide elite genetic resources for the genetic modification of efficient Fe use.