Agricultural Soil Salinity Research Articles

Impacts of groundwater dynamics around a macro-tidal river on agricultural soil salinity

Estuaries are vulnerable to oceanic and atmospheric climate change. Much of the research investigating climate change impacts on estuaries is focused on saltwater intrusion within surface water due to drought and rising sea levels, with implications for ecosystems and humans. Groundwater and soil near estuaries may also be influenced, as estuary salinity and hydraulic head changes can impact soils and aquifers not previously at risk of salinization. This study was conducted to address knowledge gaps related to present and future groundwater salinity distribution in a groundwater system connected to a macro-tidal estuary. The studied estuary experiences a tidal bore due to its hydraulic connection to the Bay of Fundy in Nova Scotia, Canada. A parcel of agricultural land adjacent to the estuary was selected to assess the groundwater response to episodic fluctuations in estuary water levels and salinity. Groundwater monitoring and electromagnetic surveys were conducted to map soil and groundwater salinity patterns. A numerical model of groundwater flow and solute transport informed by field data was used to investigate how varying estuary salinity due to droughts and sea-level rise could impact groundwater salinity. Results showed that, in contrast to salt wedges observed along marine coasts, the saline groundwater existed as a plume immediately around the estuary. Model simulations showed that short-term droughts had an insignificant impact on the adjacent groundwater salinity. However, permanent increases in salinity caused by sea-level rise increased the plume volume by 86 %, or an additional ∼11 m horizontally and ∼ 4.5 m vertically. Our results suggest that increased river salinity in this setting would not result in widespread salinization of porewater and agricultural soils, but more extensive salinization may be experienced in permeable aquifers or along more saline estuarine zones. Findings may inform land management decisions in regions exposed to increased salinity in the future.

Intervention of Soil Salinity in Agriculture of Indian Sundarbans: A review

Intervention of Soil Salinity in Agriculture of Indian Sundarbans: A review

Internet of things (IoT) assisted soil salinity mapping at irrigation schema level

Soil salinity accumulates a high concentration of salts in soils that interfere with normal plant growth. Early detection and quantification of soil salinity are essential to effectively deal with soil salinity in agriculture. Soil salinity quantification and mapping at the irrigation scheme level are vital to evaluating saline soil's reclamation activity. Existing solutions of salinity mapping are costly, time-consuming, and inadequate for applications at the irrigation scheme level. Internet of Things (IoT) assisted salinity mapping at the irrigation scheme level is proposed to quantify and map the soil salinity in agriculture. The proposed IoT-assisted salinity mapping characterizes the soil salinity in terms of Electric Conductivity, pH, and Total Dissolved Salts. The proposed IoT-assisted salinity mapping effectively observes impacts of reclamation activities in saline soil by frequent observation of soil salinity cost-effectively. The accuracy of proposed IoT-assisted salinity mapping is evaluated against the standard method of salinity measurements. The proposed IoT-assisted salinity mapping is cost-effective, and portable, which is very useful for site-specific treatments and soil zones management in saline soils.

Farmers’ adaptations strategies towards soil salinity effects in agriculture: the interior coast of Bangladesh

ABSTRACT In this study, we critically analyze the general and climate-smart adaptation strategies used by farmers in four sub-districts in southern Bangladesh to address the effects of soil salinity in agriculture. Data were collected from 360 respondents using face-to-face interviews and were analyzed using multiple analyses (variance inflation factor, ordinary least squares, Tukey’s post hoc test). The adaptations used by farmers to manage the impacts of soil salinity in agriculture were significantly influenced by their age, education, family size, farm size, level of contact with agricultural extension department officials, and their training experience. Farmers found adult education programmes particularly useful, since they focused on smart technique(s) rather than traditional approaches for agricultural development. Adaptation was comparatively more common in ‘early adapters’ and ‘early majority’ (slower to adapt) farmers. Our analysis suggests that climate-smart agriculture (CSA) programmes should be implemented in all affected sub-districts and similarly affected parts of the world. Extension workers should provide face-to-face demonstrations to affected farmers and support them with self-help programmes, which can help to attenuate and minimize the effects of soil salinity on agriculture. It will also be important to provide agricultural innovation support to affected farmers to cope with the adverse effects of soil salinity. Effective extension services are key to increasing farmers’ access to innovative information and advice. Key policy insights A philosophy of ‘learning by viewing’ for climate-smart agricultural innovations may encourage them to adopt adaptation strategies to minimize the impacts of soil salinity on agriculture. Training programmes could be offered to farmers by the Department of Agricultural Extension, especially to target innovators and early adopters of climate-smart practices, supporting them with a ‘self-help’ approach. A motivational approach and good communication skills play a vital role when introducing new adaptation strategies. A climate-smart investment plan could identify policy opportunities to further develop agriculture actions to combat climate change. Building resilience to global climate change would help to sustainably increase agricultural productivity and incomes across farming communities.

Current Advances in Plant Growth Promoting Bacteria Alleviating Salt Stress for Sustainable Agriculture

Humanity in the modern world is confronted with diverse problems at several levels. The environmental concern is probably the most important as it threatens different ecosystems, food, and farming as well as humans, animals, and plants. More specifically, salinization of agricultural soils is a global concern because of on one side, the permanent increase of the areas affected, and on the other side, the disastrous damage caused to various plants affecting hugely crop productivity and yields. Currently, great attention is directed towards the use of Plant Growth Promoting Bacteria (PGPB). This alternative method, which is healthy, safe, and ecological, seems to be very promising in terms of simultaneous salinity alleviation and improving crop productivity. This review attempts to deal with different aspects of the current advances concerning the use of PGPBs for saline stress alleviation. The objective is to explain, discuss, and present the current progress in this area of research. We firstly discuss the implication of PGPB on soil desalinization. We present the impacts of salinity on crops. We look for the different salinity origin and its impacts on plants. We discuss the impacts of salinity on soil. Then, we review various recent progress of hemophilic PGPB for sustainable agriculture. We categorize the mechanisms of PGPB toward salinity tolerance. We discuss the use of PGPB inoculants under salinity that can reduce chemical fertilization. Finally, we present some possible directions for future investigation. It seems that PGPBs use for saline stress alleviation gain more importance, investigations, and applications. Regarding the complexity of the mechanisms implicated in this domain, various aspects remain to be elucidated.

Groundwater availability and water demand sustainability over the upper mega aquifers of Arabian Peninsula and west region of Iraq

The current research is devoted to highlight the past, present and future status of groundwater characteristics over the Arabian Peninsula (AP) and west region of Iraq. The Umm er Radhuma, Rus Dammam and Neogene deposits are the major hydrostratigraphic units supplying the main groundwater resources in the AP. Water shortage is still a major problem for many countries in the world, including oil-producing countries such as Iraq, Saudi Arabia (SA), the United Arab Emirates (UAE), Qatar, Oman and Bahrain. The withdrawal of groundwater has been reflected in salinization of agricultural soils, leading to an increase in high-cost technologies such as desalination of seawater to provide suitable water for diverse sectors. Hence, the use of seawater desalination as a major source of water is unavoidable, and country development requires the use of renewable energy as protection of the environment. The need to conserve and use groundwater resources efficiently is highly essential owing to the fact that it is the only natural source of water in such developing countries of global importance. The review comprises various essential components related to groundwater variability including the hydrogeological aspects, climate change, drawdown and abstraction, rainwater harvesting, desertification and population increment. Based on the reviewed perspectives, various practical visions are discussed for better groundwater management and sustainability. This research is presented as a milestone for diverse future works and investigation that might be conducted for better water resources management over the AP region.

Adoption of disaster risk reduction strategy in agriculture sector at Southkhali Union of Sharankhola Upazila, Bangladesh

Climate change is contemporary global threat especially for coastal area of Bangladesh which drastically affects in agricultural sector. The purpose of the study was to determine the extent of adopting disaster risk reduction strategies by farmer towards agriculture sector in Southkhali union of Sharankhola upazila. Data were collected following a structured pretested interview schedule, FGD and KII and then verified with secondary sources of information. Coefficients of Correlation and regression analysis were used to find out the contribution of factors to the variation of adopting disaster risk reduction strategy by farmers in agriculture sector. The study found that the salinity was the major climate change effect in agriculture sector of this area that resulted soil salinity in agriculture and the most common adopted strategies are rain water harvesting (90%), tree plantation (89.16%) and homestead gardening (80.83%) in agriculture. Correlation analysis indicated that age (0.383**), farming experience (0.441**), communication exposure (0.271*) and organizational support (0.226*) had positive significant relationship and climate change effect (-0.266**) had negative significant relationship with adoption of disaster risk reduction strategy of farmers in agriculture. Regression analysis revealed that farming experience (β=0.546) has the strongest contribution and climate change effect (β=-0.139) had negative contribution to the adoption of disaster risk reduction strategies in agriculture. Based on this observation it can be concluded that the awareness and skill of farmer should be more developed through arranging different training program and providing necessary support to promote environmentally safe cultivation and to enhance climate change adaptation in agriculture sector.

Efecto de las sales solubles del suelo sobre las reflectancias de los cultivos y sus implicaciones en el diseño experimental.

La salinización de suelos agrícolas es uno de los factores limitantes de la agricultura moderna, por lo cual la comprensión de los efectos de este fenómeno es interés en las ciencias agrícolas. La capacidad de predicción de su avance y su monitoreo continuo permiten tomar decisiones correctas para un aprovechamiento sostenible del recurso suelo. En el presente trabajo se analiza el espacio espectral de las reflectancias de los cultivos, con énfasis especial en el caso de suelos cubiertos totalmente por cultivos en el contexto de los patrones espectrales del crecimiento. Partiendo de los efectos de la salinidad en los cultivos, se introduce el modelo bifásico de Munns y Termmat adaptándolo para el caso de espacios espectrales de la reflectancia del dosel de un cultivo. El modelo fue parcialmente validado con datos de experimentos (soya y cebada) publicados en la literatura. Del análisis de los patrones de tolerancia del experimento de cebada, resulta claro que es necesario realizar estas estimaciones bajo condiciones estandarizadas de estados de desarrollo. Los diferentes patrones de senescencia de los cultivos, inducidos por los tratamientos de salinidad, dif icultan la tarea de establecer un patrón estándar de comparación para los rendimientos y biomasas aéreas. Los resultados obtenidos son alentadores y abren una nueva forma de analizar el efecto de la salinidad sobre los cultivos, reduciendo fuertemente los costos y tiempos implicados en los diseños experimentales convencionales, mostrando que existe una ruta muy simple para obtener resultados similares a un experimento convencional de tratamientos de salinidad.

Zeta potential and electrophoretic mobility for the recovery of a saline soil with organic amendments

ABSTRACT The accumulation of salts in the soil profile produces conditions that affect the growth of crops. The effects of these conditions on crops and the intensity of these effects depend on the quantity and type of salts that predominate and are also influenced by soil characteristics and climate, among other aspects. The salinization of agricultural soils is a serious problem facing agriculture today. The use of organic amendments has increased in recent years, acting on the texture of the soil, correcting compaction or granularity problems, and influencing chemical and/or biological reactions. The objectives of this work were to analyze the use of compost and vermicompost using different analysis techniques to determine the influence of conditions on the remediation of a saline soil. In saturation extracts of soil, compost, and vermicompost, a Zeta potential value 2.34-2.44 times more negative (more-stable colloids) than that in the soil colloids was observed in the amendments. The values of electrophoretic mobility were more negative in the organic amendments compared with the soil. This is the first time that these parameters have been reported for these purposes and for a saline soil. In this study, the soil has low organic matter content (1.65%), so these amendments are expected to improve soil quality and texture, achieving the recovery of saline soils.

Remote sensing is a viable tool for mapping soil salinity in agricultural lands

Soil salinity negatively impacts the productivity and profitability of western San Joaquin Valley (WSJV) farmland. Many factors, including drought, climate change, reduced water allocations, and land-use changes could worsen salinity conditions there, and in other agricultural lands in the state. Mapping soil salinity at regional and state levels is essential for identifying drivers and trends in agricultural soil salinity, and for developing mitigation strategies, but traditional soil sampling for salinity does not allow for accurate large-scale mapping. We tested remote-sensing modeling to map root zone soil salinity for farmland in the WSJV. According to our map, 0.78 million acres are salt affected (i.e., ECe > 4 dS/m), which represents 45% of the mapped farmland; 30% of that acreage is strongly or extremely saline. Independent validations of the remote-sensing estimations indicated acceptable to excellent correspondences, except in areas of low salinity and high soil heterogeneity. Remote sensing is a viable tool for helping landowners make decisions about land use and also for helping water districts and state agencies develop salinity mitigation strategies.

Evaluating potential of borage (Borago officinalis L.) in bioremediation of saline soil

Bioremediation is an efficient, economical and environmentally acceptable strategy used for coping with the salinization of agricultural soils. In this study, borage has been proposed as possible candidate for bioremediation of Na+ and Cl−. In this order, the borage (Borago officinalis L.) seeds were sown under four levels of salinity (non-saline as control, 5, 10 and 15 dSm-1). Bioremediation and production potentials of borage were evaluated at three growth stages: seedling or early growth, vegetative and flowering stages. This study has been conducted using factorial experiment in randomized complete block design with three replications. The saline ions accumulation in company with changes in growth and chemical composition of borage was studied. The results indicated that the contents of Na+and Cl− in plants increased as salinity levels of growth medium were enhanced. The noticeable contents of Na+ and Cl− (9.096 and 5.665%, respectively) were accumulated in borage aerial parts at the highest level of salinity (EC of 15 dSm-1), whereas minimum values, 2.029 and 1.520%, occurred at non-saline condition. Although, borage growth decreased with increasing salinity, its survival/or noticeable growth indicated that this plant could tolerate salinity up to EC of 15 dSm-1. The salinity had a significant effect on the total phenol, alkaloids and tannins and their contents increased with increasing salinity. In contrast, mucilage content and swelling index significantly decreased with increasing salinity. Therefore, borage had noticeable quality and quantity yield up to salinity level of 15 dSm-1 and could cumulatively remove considerable amounts of salt from the soil. In addition, if borage can be cultivated as an inter-crop all year round at saline soil with EC up to 15 dSm-1, it can remedy saline soil in respect to Na+ and Cl−. Key words: Borago officinalis L., bioremediation, growth stage, salinity, salt tolerance.

Regional‐scale Assessment of Soil Salinity in the Red River Valley Using Multi‐year MODIS EVI and NDVI

The ability to inventory and map soil salinity at regional scales remains a significant challenge to scientists concerned with the salinization of agricultural soils throughout the world. Previous attempts to use satellite or aerial imagery to assess soil salinity have found limited success in part because of the inability of methods to isolate the effects of soil salinity on vegetative growth from other factors. This study evaluated the use of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in conjunction with directed soil sampling to assess and map soil salinity at a regional scale (i.e., 10-10(5) km(2)) in a parsimonious manner. Correlations with three soil salinity ground truth datasets differing in scale were made in Kittson County within the Red River Valley (RRV) of North Dakota and Minnesota, an area where soil salinity assessment is a top priority for the Natural Resource Conservation Service (NRCS). Multi-year MODIS imagery was used to mitigate the influence of temporally dynamic factors such as weather, pests, disease, and management influences. The average of the MODIS enhanced vegetation index (EVI) for a 7-yr period exhibited a strong relationship with soil salinity in all three datasets, and outperformed the normalized difference vegetation index (NDVI). One-third to one-half of the spatial variability in soil salinity could be captured by measuring average MODIS EVI and whether the land qualified for the Conservation Reserve Program (a USDA program that sets aside marginally productive land based on conservation principles). The approach has the practical simplicity to allow broad application in areas where limited resources are available for salinity assessment.

Transpiration and early growth of tree plantations established on degraded cropland over shallow saline groundwater table in northwest Uzbekistan

This study examined the early growth and water use of tree plantations established on a marginalized irrigated cropland in northwest Uzbekistan, where salinization of agricultural soils is widespread due to shallow saline groundwater tables. During the first two growing seasons in 2003–2004, the tree stands consisting of Elaeagnus angustifolia L., Populus euphratica Oliv., and Ulmus pumila L. were irrigated with 80 mm year −1, and, in 2005, were left to rely on the shallow (0.9–2.0 m deep) groundwater with a salinity of 1–5 dS m −1. Soil salinity increased but remained within the range of moderate-to-strong (4–14 dS m −1) during the three years. In the course of the growing season, plantations transpired 0.1–7 mm day −1 in 2003 and 1–13 mm day −1 in 2004–2005, as determined with the Penman–Monteith model. In the absence of irrigation, the annual stand transpiration averaged 1250, 1030, and 670 mm for E. angustifolia, P. euphratica and U. pumila, respectively. In 2005, the leaf area index of E. angustifolia ranged from 5 to 10, surpassing that of the other two species more than two-fold. Differences in canopy conductance and transpiration were significant among the tree species and the decoupling coefficient at no time exceeded 0.3, indicating strong physiological control of transpiration. The vigorous juvenile growth and high transpiration under deficit irrigation and after irrigation was terminated, suggested that afforestation with well-adapted tree species is a viable land use option for degraded cropland. The plantation responses to increasing soil salinity must be monitored to determine potential leaching demands in the long run.

In Vitro Ranking of Salinity Tolerance in Potato (Solanum sp.)

Globally, salinization of agricultural soils is an increasing problem. At least 25% of the world's cultivated land area is now salt-affected. Although the potato (Solanum tuberosum L.) is among the most important of crops plants, little is known of the range of salt tolerance among cultivars of S. tuberosum, wild Solanum sp., or their hybrids. The objective of this work was to rank the salinity (NaCl) tolerance of 200 North American and European cultivars, 13 hybrids of S. chacoense, S. tuberosum, and primitive cultivated diploids (S. phureja and/or S. stenotomum) and their progenies, and 14 accessions of S. chacoense from different collection sites. This was done in vitro, using a modified nodal cutting bioassay. The parameters evaluated included shoot and root lengths, and fresh and dry weights. Extreme variation for salinity tolerance was noted among the cultivars, the hybrids, and the wild species.

Economic impact of soil salinity in agriculture. A case study of Bardenas area, Spain

This study analyses the economic damage resulting from high soil salinity levels in the irrigated lands of Bardenas I in Zaragoza, Spain. The STEM method, an interactive multi-objective programming technique, is used to represent the current situation with the corresponding salinity levels. The approach developed is then used to simulate the future situation. An economic analysis is carried out to demonstrate the feasibility of salt-affected soil reclamation.