Soil Salinity Management Research Articles

Mulched drip irrigation: a promising practice for sustainable agriculture in China’s arid region

The long-term practice of mulched drip irrigation (MDI) has significantly advanced cotton production in China’s arid regions. In this study, we conducted an evaluation of the changes to key soil environmental factors within cotton fields under MDI, providing a holistic assessment of MDI sustainability. Specifically, long-term MDI demonstrated numerous benefits including improved soil salinity management, nutrient retention, soil structure, and microbial functions. Collectively, these changes contribute to enhanced overall soil quality. Our research also confirms MDI as an effective integrated water-saving technology approach. Affirming the sustainability of widespread MDI promotion, our findings firmly support its potential as a sustainable and viable solution for oasis agriculture in arid lands, conferring long-term benefits to agricultural production in these regions.

Combating Soil Salinity in Sugarcane Farming: Integrated Approaches and Bio-saline Agriculture Innovations

Sugarcane, a vital commercial crop globally, faces significant challenges due to soil salinity, particularly in India where regions such as Gujarat, Uttar Pradesh, Maharashtra, West Bengal, and Rajasthan are notably affected. Salinity impairs sugarcane growth through reduced water uptake, ion toxicity, nutrient imbalance, stunted growth and soil structure degradation. To combat these issues, various strategies have been proposed, including improving drainage, leaching, selecting salt-tolerant varieties, optimizing irrigation, and using soil amendments. Bio-saline agriculture, incorporating plant growth-promoting rhizobacteria (PGPR) and salt-tolerant plants, offers an innovative approach by enhancing soil fertility and crop resilience under saline conditions. Additionally, research indicates that long-term irrigation practices can exacerbate soil salinity, altering key soil parameters such as pH, electrical conductivity and sodium levels. Studies on spent wash application show variable impacts on sugarcane yield and quality, with optimal results observed at moderate application rates. Effective management of soil salinity through these combined approaches can mitigate adverse effects and improve sugarcane productivity and sustainability.

Effects of Drip Irrigation Flow Rate and Layout Designs on Soil Salt Leaching and Cotton Growth under Limited Irrigation

Optimal drip irrigation management in shallow groundwater areas needs to clarify the effects of flow rate and layout designs on the soil moisture, salt distribution, cotton root length density, plant height, leaf area, and yield. In this study, a one-year field experiment was conducted from April to October 2018 in the fifth company of the 16th Regiment in Alar City, Xinjiang, to investigate the effects of various drip flow rates and layout designs of cotton growth. Two drip flow rates (2.8 and 5.6 L·h−1) and two layout designs (one film, two drip tapes, and six rows; one film, three drip tapes, and six rows) were applied to explore the optimal combination, resulting in a total of four treatments that were irrigated three times in the whole growth period. Soil moisture, salt distribution, cotton root length density, plant height, and leaf area were measured. The main results were as follows: (1) Under the same layout designs, the soil moisture content was higher and the soil salinity was lower when the drip flow rate was 5.6 L·h−1, and the cotton root length density, plant height, leaf area, and yield were significantly higher than that of 2.8 L·h−1. (2) Under the same drip flow rate, the soil desalination rate, cotton growth indexes, and yield under the three-tapes treatment were significantly higher than the values of the two-tapes treatment. The actual yield of treatment D was 21.56%, 19.23%, and 11.71% higher than that of treatments A, B, and C, respectively. (3) The crop evapotranspiration of cotton during the two irrigation cycles showed an increasing trend, and the groundwater contribution showed a smaller and then increasing trend. Overall, the combination of three tapes and a drip flow rate of 5.6 L·h−1 had the highest cotton yield and net income, which were 6211.36 kg·hm−2 and 4820.21 kg·hm−2 for the theoretical and actual yields. The results of this study can provide a reference for the management of limited irrigation leaching soil salinity and cotton cultivation in shallow groundwater areas.

Detection of soil salinity distribution and its change in the Yellow River Delta comparing 2006 and 2022

AbstractThe Yellow River Delta (YRD) has the world's highest land formation rate. However, soil salinization has caused severe land degradation in the region. Understanding the distribution of soil salinity and its variation is essential for saline soil management. This study combined soil salinity sampling data, remote sensing imagery, and layers of geographic environmental factors. Three different models, including Ordinary Kriging (OK), Geographically Weighted Regression (GWR), and Bayesian Maximum Entropy (BME), were used and compared to predict the soil salinity of two soil layers in 2006 and 2022. Then the spatial distribution characteristics and development trends of soil salinity in the YRD were analyzed. The results indicated that (1) The BME model is an optimal salinity prediction model that integrates soft data from multiple sources to perform nonlinear estimates. Compared to the OK and GWR models, the RMSE was reduced by up to 25% and 13%, respectively, and the greatest improvement in R2 was increased from 0.0534 and 0.2718 to 0.5569, respectively. (2) Soil salinity in the YRD shows a spatially increasing trend from the southwestern inland to the northeastern coast. Over the past 16 years, the salinization pattern has become more complex: soil salinization has been mitigated in the central and southern regions, with the average salinity decreasing from 1.03% to 0.86% and the salinization rate decreasing from 99% to 88%; and it has significantly intensified in the northern part of the study area near the old Yellow River channel and the Gubei Reservoir, and in some scattered inland areas. Continuous water and sediment regulation in the Yellow River basin and ecological management of natural reserves can generally alleviate soil salinization, but the risk of soil salinization can be increased by seawater erosion, inappropriate land use, and resource exploitation.

Characterization and Mapping of Soil Salinity Status at Small-Scale Irrigation Farm: The Case of Fantale Irrigation Project Sites

Agricultural production and productivity can be adversely affected by the presence of excessive salts in soils particularly in semi-arid and arid areas. Knowledge of the salinity/sodicity of the soil and the quality of the irrigation water is essential for managing agricultural fields effectively and increasing the output and productivity of the lands. This research was initiated with the objectives of characterizing and Mapping of soil salinity status at small scale irrigated areas of Fantale district and identifying the most affected irrigation scheme so as to design appropriate soil salinity management. The study was conducted at Fentale district of Galcha, Gola and Dire Sade irrigation schemes. Soil samples were collected from the surface using augur, and from pits at different depth interval and analyzed for pH, EC, Na+, ESP, SAR, Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup>, and CEC. The result was compared with the standards set by FAO system to classify soil and water salinity. Accordingly, it was identified that Galcha irrigation scheme was characterized as sodic due to very strong sodium concentration with average ESP of 53.2% and EC 3.95 mmhoms/cm and pH about 9.25. On the other hand, Gola and Dire Sade Irrigation schemes were characterized as moderately and slightly sodic respectively. Sodium was the dominant soluble cation, followed by calcium, magnesium, and potassium in all soil depths and schemes. Beside primary Salinization of natural processes such as physical or chemical weathering parent material, and discharge Basaka Lake to the downstream, was the main source of salt build-up in the upper layers of the soil at Galcha irrigation scheme. On the other hand, irrigation water analysis indicated that water used for irrigation at all irrigation schemes were slightly sodic. Therefore, the study underscores the need for a scientific reclamation of sodic soils primarily at Galcha Irrigation scheme where sodium concentration in the soil was very strong.

Estimating soil salinity in mulched cotton fields using UAV-based hyperspectral remote sensing and a Seagull Optimization Algorithm-Enhanced Random Forest Model

Xinjiang is a crucial production base for mulched cotton fields but faces increasingly severe challenges of soil salinization. Under the current drive towards precision agriculture, high precision monitoring of agricultural conditions at the field scale has become critical. Traditional remote sensing technologies are limited by insufficient spatial and spectral resolution, making field monitoring under mulched conditions exceptionally challenging. This study introduces a novel approach combining drone-based hyperspectral remote sensing with the Seagull Optimization Algorithm-Enhanced Random Forest Model (SOA-RF). After employing the preprocessing techniques of standard normal variable (SNV) and fractional order derivative (FOD), we employed the model to assess the level of field-scale salinization under optimization of feature selection using separate dimensionality reduction algorithms (sequential projection algorithm (SPA), optimal band combination analysis (OBCA)) and a combined approach (SPA-OBCA). The following main results were found: (1) SNV and FOD enhanced the spectral characteristics of cotton canopies, with the FOD technique performing better in detecting subtle signal changes in the positive and negative peaks of the spectrum. (2) SPA and OBCA were effective in screening the soil salt-sensitive bands in cotton canopies but the combined SPA-OBCA method provided a better selective preference for hyperspectral bands, with an optimal correlation of 0.926. (3) The model combined the advantages of SOA with the power of Random Forest to optimize the parameters and improve the estimation accuracy (R2 = 0.925, RPD = 4.128). We used unmanned aerial vehicle hyperspectral imagery to create a 5-cm resolution map of soil salinity distribution in cotton fields that allowed detection of differences in soil salinity between mulches, thus providing a scientific basis for soil salinity management and the development of precision agriculture.

Evaluating the Performance of the AquaCrop Model to Soil Salinity in Jordan Valley

The demand to apply a decision support system to simulate salinity and drought is increasing with time, particularly in arid and semi-arid regions like Jordan, where the threat of land degradation by salinization is of high concern. The main objective of this research was to evaluate the response of the AquaCrop model to soil salinity in Jordan Valley. Two experiments were conducted, one at the field and the other at the greenhouse. Three water salinity levels (S): S1 (control = 2 dS m−1), S2 (4 dS m−1), and S3 (8 dS m−1) with three irrigation amounts (R): R1 (control = 120%), R2 (100%), and R3 (70%) were used in the field. Four levels of saline water (S):S1 (control =0.65), (4) S2, (8) S3, and (10) dS m-1) S4 were used in the greenhouse. In both experiments, grain yield, and aboveground biomass were measured after harvesting. Soil salinity and pH were measured every three weeks during the growing season to monitor soil salinization. Results showed that the final field grain yield was good in calibration and validation, with a 0.96 agreement index (d). The efficiency factor (E) was 0.86 and 0.87 for calibration and validation, respectively, while the normalized root mean square error (NRMSE) was less than 4 %. Field biomass d-index of 0.87 and 0.71 and E of 0.65 and 0.45 for Calibration and Validation were found, respectively. In the greenhouse experiment, the results were less satisfactory. Grain yield showed d-index of 0.84 and 0.88 in calibration and validation, respectively, while biomass showed poor results. All statistical criteria used in this research indicated that the model can simulate grain yield and biomass properly in the field, however, biomass statistical results were less accurate. Overall it is recommended, to use AquaCrop for soil salinity management in Jordan Valley.

Mulch and efficient microorganisms: effects on the management of soil salinity in banana

Mulch consists of covering the surface layer of the soil with plant or organic residues, preventing moisture loss, reducing weeds, and increasing microbiological activity. Efficient microorganisms work by breaking down organic matter to store carbon, together with biochar, retaining nutrients and improving its biological capacity. The high presence of salts harms and degrades the soil structure, reducing water permeability, and causing severe issues in the root system and foliage of the plant. In this case, the research objective is to evaluate the effects of mulch and efficient microorganisms on salinity management in banana cultivation. Three treatments were performed: T1 (mulch, 10g biochar, 10g silicon); T2 (mulch, 10g biochar, 10g silicon, 10g microorganisms, 35g rooting agent); T3 (mulch, 10g biochar, 10g silicon, 10g microorganisms, 35g rooting agent, 70ml physiological regulator). T2 and T3 significantly lowered soil electrical conductivity, improving nutrient availability and percentages of functional roots in the banana crop, which has a positive impact on plant growth and development. These results highlight the importance of considering these agricultural practices to optimize banana production.

Addressing salinity challenges: A comprehensive analysis of saline water and salt-tolerant soil for sustainable crop production in UC Tando Qaiser, Sindh, Pakistan

This study focuses on the physico-chemical characteristics of soils in UC Tando Qaiser, District Hyderabad, Sindh, Pakistan, irrigated by tube well water. The soil samples were collected at depths of 0-20, 20-40, and 40-60 cm, and their particle size distribution, organic matter content, pH, and salinity were analyzed. Results indicate that the soils are heavy in texture, likely influenced by the parent material deposited by the Indus River. Organic matter content was found to be low, possibly due to the absence of farmyard manure and limited cultivation of green manure crops. The majority of soils exhibit a slightly to medium alkaline reaction, characteristic of calcareous soils with high Ca2+, Mg2+, and K+ content. Slightly-saline soils were observed, emphasizing the need for soil salinity management. Tube well water analysis revealed variations in electrical conductivity, with some samples exceeding permissible limits. Recommendations include strategies to enhance organic matter, mitigate soil salinity, and implement regular monitoring of tube well water quality for sustainable agriculture in the region.

Spatial assessment and chemical characterization of degraded (salt-affected) soils at post-reclamation stage of the Indo-Gangetic Plain in Haryana State.

Dynamics of soil salinity and sodicity is a common feature driven by anthropogenic causes such as soil reclamation, the effect of extreme climate events, disturbed salt, and water balance in irrigated areas that are devoid of any good quality groundwater source and adequate natural surface drainage condition in a semiarid climatic region. Periodic soil salinity assessment is therefore vital to know the current soil salinity status, plan reclamation, and/or management strategies for sustained agricultural growth and livelihood security. Temporal studies using Indian Remote Sensing (IRS) LISS III data, at pre- (1997) and post-reclamation (2017) stages have indicated spatial changes as reclaimed areas (~ 35%) and dynamics of soil salinity as increased areas (~ 61%) under irrigation across the Gangetic plain of Haryana State. The prominent areas of reclaimed sodic soil soils were located in the old alluvial plain which covered Panipat (12.32%), Karnal (6.01%), and Jind (5.9%) districts. Based on pH, ECe, and ESP values, these were classified as slight (Sso1, 8.75%), moderate (Sso2, 24.73%), and strong (Sso3, 18.20%) sodic soils, respectively. Significant salinity-inflictions (emerging areas) were identified at low-lying, poorly drained, irrigated soils in south and central Haryana that cover Jhajjar (13.99%), Sirsa (11.06%), Hisar (10.15%), Rohtak (8.73%), Bhiwani (6.43%), Palwal (4.31%), and Rewari (3.01%) districts. Slight (Ssa1, 16.82%), and moderate (Ssa2, 22.13%), categories are dominant soils, respectively. Among the landforms, significant areas (28.24%) were identified in the old alluvial plain with sand dunes (OAPSD), aeo-fluvial plain (AFP, 8.6%), and fluvio-aeolian plain (FAP, 6.0%), respectively. Dominant areas of reclaimed soils (14.4%) were identified in OAPSD. The soil analysis data indicated that these soil are moderate to strongly sodic (pH 8.7-11.0) and saline (ECe 4-26 dS m-1). The reclaimed sodic soils showed prominent improvement in soil pH and sodicity levels (pH 8.3-9.2) at 0-15cm depth and are commonly located in the Ghaggar and Yamuna river plains. Poor quality groundwater with high Residual Sodium Carbonate (RSC) was dominant at selected locations under the arid and semiarid climate. The database can also be used as a reference database for further monitoring of soil salinity status particularly in the irrigated regions. Currently, it is also used as a primary database for harmonization, monitoring, and reconciling of similar soils of the world under the Global Soil Partnership projects.

Sustainable Management of Soil Salinity with Special Reference to Smart Fertigation Systems

Sustainable Management of Soil Salinity with Special Reference to Smart Fertigation Systems

Perceptions and attitudes of farmers and landowners on soil salinity management and use of elemental sulphur in Oman

AbstractSoil salinity threatens agricultural sustainability globally and is a significant challenge in Oman. Previous studies in Oman focused on examining the causality and spatiotemporal variation of groundwater and soil salinity, neglecting farmers' perceptions and attitudes towards salinity management. Therefore, this study evaluates (i) perceptions and attitudes of landowners and farmers towards soil salinity and its management, and (ii) determinants of willingness to use elemental sulphur to alleviate soil salinity in Oman. A questionnaire survey (122 responses) assessed perceptions, attitudes and knowledge using Likert scales and qualitative questions. Binary Logistic Regression analysed determinants of willingness to use elemental sulphur. Results reveal variations in perceptions, attitudes, knowledge and management practices. Most of the respondents were aware of adequate nutrient and water requirements for crops (p < .05). Respondents rely on social media (38.5%), fellow farmers (32.1%) and personal experiences (11.5%) for knowledge acquisition about soil salinity management. Half of the respondents did not monitor soil salinity, while the other half relied primarily on visual observation. A substantial number (62.6%) of the respondents did not implement any techniques to alleviate soil salinity, while among those who acted, a majority preferred cultivating date palms (55%) or fodders (29.4%). Awareness of the national salinity management strategy and commercial products is lacking. However, when introduced to elemental sulphur as a soil amendment for salinity, 74.8% of the respondents demonstrated a willingness to utilize it. Most (82.4%) preferred elemental sulphur products within the lowest price range. Being a full‐time farmer, owning a farm, awareness of the national strategy and low‐price preferences were positive determinants, while <1 year of farming experience was a negative determinant of willingness to use elemental sulphur. These findings inform future research on socio‐economic perceptions of salinity in Oman, the Gulf region and similar arid areas facing food production limitations.

Subsurface irrigation with ceramic emitters improves the yield of wolfberry in saline soils by maintaining a stable low-salt environment in root zone

The high salt concentration in soils depresses crop growth and saline soil reclamation. An appropriate irrigation method is essential to alleviate water shortage and promote wolfberry (Lycium barbarum L.) cultivation in saline soils. Subsurface irrigation with ceramic emitters (SICE) is a novel technique that maintains a stable soil water environment through adaptive outflow and holds a beneficial impact on saving water and increasing yield. However, the effect of SICE on salt leaching remains to be investigated. A field experiment was executed to investigate the salt leaching process in SICE and subsurface drip irrigation (SDI) in saline soils and their effect on wolfberry yield. HYDRUS-2D was calibrated and validated using experimental data to investigate the spatial-temporal variation of soil salinity. Subsequently, the salt leaching efficiency with different emitter discharges (0.10, 0.15, 0.24, and 0.33 L h−1) was assessed via HYDRUS-2D. Results indicated that SICE leached soil salt below the stress threshold after 50 days of irrigation, while SDI required 148 days. At the end of irrigation, SICE formed a low-salt zone that occupied 74.14% of the main root zone, while the zone with SDI was 60.69%. Generally, SICE provided a stable low-salt environment for wolfberry root system for 117.5 days (69.9% duration of growth period). SICE improved the wolfberry yield and root-zone soil desalination efficiency (DE) by 0.17 t ha−1 and 0.41% cm−1 than SDI, respectively. When emitter discharge increased to 0.24 L h−1, the root zone of wolfberry was protected from salt stress, but DE decreased gradually. SICE with an emitter discharge of 0.24 L h−1 was recommended for wolfberry in saline soils of Ningxia. The results reveal that SICE is an efficient salt leaching method for saline soil management and crop yield improvement.

Soil salinity management practices in coastal area of Bangladesh: a review

Soil salinity is a significant threat to agriculture and livelihood, particularly in the Southern coastal areas of Bangladesh. Soil salinity is extended from 0.833 to 1.056 million hectares (about), with an increase of 26% between 1973 and 2009. Out of about 1.689 million hectares of coastal land, about 1.056 million hectares are affected by soil salinity of various degrees covering 49 Upazila (sub-district) of 19 districts. About 0.328, 0.274, 0.189, 0.161, and 0.101 million hectares of land are affected by very slight (S1), slight (S2), moderate (S3), strong (S4), and very strong salinity (S5), respectively. Data recorded by SRDI manifests new ingression of salinity in Narail (18.71 ha), Jashore (14.99 ha), Barishal (13.96 ha), Gopalgonj (6.27 ha), Jhalakati (4.69 ha), and Madaripur (0.72 ha) districts. Soil salinity also encroached a large area of Bhola (53.84 ha), Patuakhali (40.08 ha), Khulna (27.92 ha), and Bagerhat (23.14 ha), besides minor ingression in other districts. The salinity level is almost double (2.8-18.5 to 4.0-42.8 dS/m) from 1973 to 2009 in Sharankhola Upazila of Bagerhat district, Dumuria Upazila of Khulna district and Shyamnagar Upazila of Satkhira district (SRDI, 2010). Different causes are involved in increasing the water and soil salinity of the coastal area of Bangladesh, like withdrawal of fresh river water from upstream, irregular rainfall, faulty management of sluice gates and polders, regular tidal water flooding in an unprotected area, the capillary rise of soluble salts, decreased surface water availability, lowered ground water table, reduced soil moisture content, the introduction of unplanned shrimp cultivation, lack of drainage facilities. Some of the widespread soil and land management techniques adopted in the saline areas of Bangladesh to cope with the salinity are polder (123), farm-pond (khamar-pokor), sarjan procedure, usage of raised shrimp farm bund for year-round cropping, mulching (keeping land covered in winter and summer months), land leveling, pitcher (kolosh) irrigation to grow watermelon, dibbling method, the addition of organic matter, chemical fertilizers and cultivation of saline tolerant crop varieties, particularly rice. Vol. 10, No. 1, April 2023: 1-7

Engineering Approach for Production of Arbuscular Mycorrhizal Inoculum Adapted to Saline Soil Management

(1) Background: Soil salinity impacts plant growth and productivity in steppic regions. Thus, the current study aims at producing, at low cost, an inoculum composed of native arbuscular mycorrhizal fungi (AMF) strains adapted to saline soil management. (2) Methods: The propagation of the native AMF strains was carried out in three natural saline soils presenting increasing salinity levels (4.5, 8.5 and 9.3 dS·m−1 in Boughzoul (BG), Salt Rocket (SR) and Zaafrane (ZA) sites, respectively). Three host plant species (alfalfa, clover and leek) were tested as trap cultures. AMF spore richness and diversity, the quantification of soil microbial biomass and the determination of the most probable number (MPN) were carried out before and after 24 months culture. Moreover, the mycorrhizal rates of the host plant species were assessed. (3) Results: The moderate saline soil (SR) planted with alfalfa was found to be the most suitable for AMF inoculum production with a maximum of 650 spores, 10 g−1 of soil, a mycorrhizal rate of 86%, 70 propagules·g−1 of soil and the highest microbial biomass content. (4) Conclusion: This study points out the best combination for the production of a more adapted AMF biofertilizer for saline soil management and proposes several indicators for biofertilizer quality evaluation.

Current Status and Development Trend of Soil Salinity Monitoring Research in China

Soil salinization is a resource and ecological problem that currently exists on a large scale in all countries of the world. This problem is seriously restricting the development of agricultural production, the sustainable use of land resources, and the stability of the ecological environment. Salinized soils in China are characterized by extensive land area, complex saline species, and prominent salinization problems. Therefore, strengthening the management and utilization of salinized soils, monitoring and identifying accurate salinization information, and mastering the degree of regional salinization are important goals that researchers have been trying to explore and overcome. Based on a large amount of soil salinization research, this paper reviews the developmental history of saline soil management research in China, discusses the research progress of soil salinization monitoring, and summarizes the main modeling methods for remote sensing monitoring of saline soils. Additionally, this paper also proposes and analyzes the limitations of China’s soil salinity monitoring research and its future development trend, taking into account the real needs and frontier hotspots of the country in related research. This is of great practical significance to comprehensively grasp the current situation of salinization research, further clarify and sort out research ideas of salinization monitoring, enrich the remote sensing monitoring methods of saline soils, and solve practical problems of soil salinization in China.

Promising management strategies to improve crop sustainability and to amend soil salinity

By affecting 10% of the world’s total arable land, soil salinity has become a potential threat to feeding the exploding population. As per the current scenario, among 1,125 million hectares of salt-affected land, nearly 76 million hectares are seriously affected due to human-induced salinization. Due to soil salinization, crop productivity is being hampered. In order to enhance productivity, there is an urgent need to shift from traditional methods to advanced 3E (efficient, economic, and environmentally sound) technology for soil salinity reclamation and management to achieve better soil health and sustainable crop production. The detailed mechanism of salt interference with various pathways involved in plant growth and development needs to be understood. This article critically reviews the mechanism of harmful salt interference with nutrient dynamics in soil and various physiological pathways involved in crop growth to apply various soil-oriented (crop residue management, biochar application, and agroforestry system) and plant-oriented [plant growth-promoting microbes (PGPMs), plant growth regulators, and nanotechnology] promising reclamation and rehabilitation approaches to mitigate its hazardous effect on soil salinity. The monitoring and assessment of salt-affected soils through remote sensing (RS) and geographical information systems (GISs) are pivotal in the management and framing of long-term policies to confront alarming threats to crop productivity and sustainability. This study provides an insight into recent developments in soil salinity management and proposes futuristic solutions that could ameliorate soil salinity to attain crop sustainability under adverse environmental conditions.

Effect of Irrigation Level and Sowing Date on Yield of Field Bean in Saline Soils of Konkan Region of Maharashtra

A field experiment was conducted during consecutive Rabi seasons of 2019-2020 and 2020-2021 in coastal saline soils at Khar Land Research Station, Panvel, Maharashtra, India to study the effect of different sowing dates and irrigation levels on the production potential of field bean. The experiment was laid out in factorial randomized block design (FRBD) with four replications, comprising three dates of sowing viz., immediately after harvest of paddy (D1), 10 days after harvest of paddy (D2), and 20 days after harvest of paddy (D3); and three irrigation levels viz., no irrigation (I0), one irrigation at flowering (I1), and one irrigation each at flowering and at pod formation (I2). The results showed that the treatment D1 recorded significantly higher seed yield of field bean (915 kg.ha-1) over D2 (713 kg.ha-1) and D3 (605 kg.ha-1). Among the irrigation levels, treatment I1 resulted in significantly higher seed yield of field bean (856 kg.ha-1) over I2 (726 kg.ha-1) and I0 (650 kg.ha-1). The treatment combination I1D1 produced significantly higher seed yield of field bean (1065 kg.ha-1) with higher net realization (1,06,500 ₹.ha-1), net income (55,222 ₹.ha-1) and benefit cost ratio (2.08). Both sowing date and irrigation level played important role in management of root zone soil moisture and soil salinity which influenced the seed yield. Sowing of field bean immediately after the harvest of paddy and providing one irrigation at the time of flowering is recommended to obtain better yield and returns from the field beans cultivated in Konkan region of Maharashtra.

Inversion of soil salinity in China's Yellow River Delta using unmanned aerial vehicle multispectral technique.

The rapid and accurate acquisition of soil property information, especially the soil salinity (SS), is required for saline soil management in the Yellow River Delta (YRD). In this study, Lijin County and Kenli District were selected as study area. Unmanned aerial vehicle (UAV) multispectral data and soil sample data were acquired from March 25 to 28, 2019. Pearson correlation and gray correlation analyses were first used to screen sensitive spectral bands/indices, which were used for model parameters construction. Three machine learning and one statistical analysis methods were used to construct the SS inversion models. The results found that the gray correlation coefficient value were greater than the Pearson coefficient value for all bands and indices. Based on the gray correlation coefficient, nine sensitive bands and indices were selected to construct 18 model parameters. By comparing the 4 models, it was concluded that the BPNN model had the highest inversion accuracy, and its calibration coefficient of determination (R2) and root mean square error (RMSE) were 0.769 and 1.342, respectively. The validation R2 and RMSE were 0.774 and 1.975, respectively, and the relative prediction deviation (RPD) was 2.963. The SS estimation results based on BPNN model were consistent with those of the field investigation. Rapid and accurate inversion of SS based on UAV multispectral technique was achieved in this study, which provides technical support for regional management.

The PGPR Mechanisms of Salt Stress Adaptation and Plant Growth Promotion

Worldwide crop productivity hampers severely due to the adverse effects of salinity. Global warming causes a rapid escalation of the salt-affected area, and new agricultural land is affected through saltwater intrusion. The ever-growing human population impulses to utilize the saline area for crop cultivation to ensure food security. Salinity resistance crops could be a promising substitute but with minor success because inappropriate tactics on saline soil management resulted in unsatisfactory yield. Salt-tolerant plant growth-promoting rhizobacteria (ST-PGPR) is considered an alternate way towards enhancing crop growth in saline ecosystems. It is reported that PGPR is enabled to produce exopolysaccharides which lead to biofilm formation and generate osmoprotectants and antioxidant enzymes that can significantly contribute to stimulating plant growth in the saline ecosystem. In addition, several plant growth-promoting characteristics of PGPR such as the acquisition of essential nutrients and upsurge hormone production could enhance plant growth simultaneously. In this review, we will explore the survival mechanisms of ST-PGPR and their influence on plant growth promotion in saline ecosystems.