Maximising ecological value and assessing land suitability for sustainable grassland management in Asia's largest tropical grassland, Western India.

Grasslands are crucial ecosystems that provide numerous ecological services and support biodiversity conservation. Grasslands undergo significant threats from both anthropogenic and natural sources, compromising their ability to maintain biodiversity, ecosystem services, and human well-being. However, grasslands are frequently ignored in sustainable development objectives. Adequate knowledge of how grassland degradation affects ecosystem services is essential for sustainable management and grassland ecological restoration. The Kachchh region in western India harbours a unique grassland ecosystem known as the Banni grassland, which once became the finest grassland in Asia. However, undesirable anthropogenic interventions have accelerated its degradation. This research paper aims to assess the suitability of different land areas in Banni for sustainable grassland restoration, considering ecological value as a primary criterion. In the present research, land suitability for grassland management was assessed using a geographical information system (GIS)-based multi criteria evolution (MCE) method with satellite data and the analytic hierarchy process (AHP). The ground truthing of the soil samples was carried out alongside. Slope, rainfall, infiltration rate, LULC, geomorphology, soil texture, soil organic carbon, water holding capacity, SAR, CEC, pH, EC, and soil nutrients were among the criteria used. The weights for each criterion were calculated using a pairwise comparison matrix, and the scores were allocated to sub criteria based on field work, expert opinions, and a literature review. The proposed method can be very useful for evaluating the state of the land and can help with the best possible planning for grassland development and conservation. Banni grassland has the potential to be developed into a critical zone observatory (CZO) in the future, and the present study, with further inputs, holds promise for furthering the cause of its sustainable management. Overall, this study underscores the importance of assessing land suitability for sustainable grassland management and highlights the potential for maximising the ecological value of grasslands in western India and beyond.

Changes in Salinity, Mangrove Community Ecology, and Organic Blue Carbon Stock in Response to Cyclones at Indian Sundarbans.

Climate change-induced frequent cyclones are pumping saline seawater into the Sundarbans. Fani, Amphan, Bulbul, and Yaas were the major cyclones that hit the region during 2019-2021. This study represents the changes in the soil parameters, mangrove biodiversity and zonation due to the cyclone surges in the Indian Sundarbans between 2017 and 2021. Increasing tidal water salinity (parts per thousand) trends in both pre-monsoon (21 to 33) and post-monsoon (14 to 19) seasons have been observed between 2017 and 2021. A 46% reduction in the soil organic blue carbon pool is observed due to a 31% increase in soil salinity. Soil organic blue carbon has been calculated by both wet digestion and the elemental analyzer method, which are linearly correlated with each other. A reduction in the available nitrogen (30%) and available phosphorous (33%) in the mangrove soil has also been observed. Salinity-sensitive mangroves, such as Xylocarpus granatum, Xylocarpus moluccensis, Rhizophora mucronata, Bruguiera gymnorrhiza, and Bruguiera cylindrica, have seen local extinction in the sampled population. An increasing trend in relative density of salinity resilient, Avicennia marina, Suaeda maritima, Aegiceras corniculatum and a decreasing trend of true mangrove (Ceriops decandra) has been observed, in response to salinity rise in surface water as well as soil. As is evident from Hierarchical Cluster Analysis (HCA) and the Abundance/Frequency ratio (A/F), the mangrove zonation observed in response to tidal gradient has also changed, becoming more homogeneous with a dominance of A. marina. These findings indicate that cyclone, climate change-induced sea level rise can adversely impact Sustainable Development Goal 13 (climate action), by decreasing organic soil blue carbon sink and Sustainable Development Goal 14 (life below water), by local extinction of salinity sensitive mangroves.

The game changing role of traditional ecological knowledge based Agri amendment systems in nutrient dynamics in the stress prone semi arid tropics.

The major crop nutrients determine the nutritional content and vigor of crops. The deficiency or occurrence below minimal level of any of the nutrients are often seen as a cause of poor growth or complete crop failure. The present study was an attempt to understand the impact of Traditional Ecological Knowledge (TEK) (A1)vis-à-vis conventional chemical intensive (A2)agriculture amendment systems in altering/modifying the nutrient dynamics of the soil with respect to nitrogen (N), phosphorus (P), potassium (K) and sulphur (S), calcium (Ca), magnesium (Mg) levels in the pre, mid and post-harvest phases of crop in six cropping seasons spread across four years. The study area was a geo-ecologically unique terrain of Kachchh, Western India, a typical representative of allied arid and semi-arid tropics that are prone to various natural threats and stressors like drought, salinity and erratic rainfall pattern that affect the agri-management activities. Seasonal amendment data, clearly depicts that TEK based systems were efficient in soil organic carbon (SOC) accrual over seasons, an important trait required in challenging settings of tropical aridisols. The major primary (N, P, K) and secondary (S, Ca, Mg) nutrients were at par or higher than integrated chemical intensive systems. TEK based amendments ensured proper and timely management of nutrients in the soil. This inherent value addition offered by indigenous manure applications is an important step in climate change mitigation measures and overall agricultural sustainability.

Neurospora sp. SR8, a novel phosphate solubiliser from rhizosphere soil of Sorghum in Kachchh, Gujarat, India.

Phosphorus (P) is abundant in soils in both inorganic and organic forms; nevertheless, it is unavailable to plants due to its fixation. Phosphate solubilising microorganisms including fungi play a pivotal role in making P available for plants by the process of solubilisation and mineralisation. Among the fungi that solubilize phosphate, the genera Aspergillus and Penicillium are the most representative although strains of Trichoderma and Rhizoctonia solani have also been reported as P solubilizers. Here, we report Neurospora discreta strain SR8 (NCCS Pune accession No. MCC1096 and NCBI accession No. KJ676544) as a P solubiliser as the first report. The strain was isolated from rhizospheric soil of Sorghum bicolor (L.) Moench. grown in semi-arid climate of a unique ecological zone of Kachchh, western India. The organism was identified on the basis of morphological characterization and by sequencing of ITS region. The strain SR8 survived the stressed environment in terms of high salinity and low precipitation rate in this area and could be a potent P solubiliser in stressed environments.

Phosphate solubilizing microbes: sustainable approach for managing phosphorus deficiency in agricultural soils.

Phosphorus is the second important key element after nitrogen as a mineral nutrient in terms of quantitative plant requirement. Although abundant in soils, in both organic and inorganic forms, its availability is restricted as it occurs mostly in insoluble forms. The P content in average soil is about 0.05% (w/w) but only 0.1% of the total P is available to plant because of poor solubility and its fixation in soil (Illmer and Schinner, Soil Biol Biochem 27:257-263, 1995). An adequate supply of phosphorus during early phases of plant development is important for laying down the primordia of plant reproductive parts. It plays significant role in increasing root ramification and strength thereby imparting vitality and disease resistance capacity to plant. It also helps in seed formation and in early maturation of crops like cereals and legumes. Poor availability or deficiency of phosphorus (P) markedly reduces plant size and growth. Phosphorus accounts about 0.2 - 0.8% of the plant dry weight. To satisfy crop nutritional requirements, P is usually added to soil as chemical P fertilizer, however synthesis of chemical P fertilizer is highly energy intensive processes, and has long term impacts on the environment in terms of eutrophication, soil fertilility depletion, carbon footprint. Moreover, plants can use only a small amount of this P since 75-90% of added P is precipitated by metal-cation complexes, and rapidly becomes fixed in soils. Such environmental concerns have led to the search for sustainable way of P nutrition of crops. In this regards phosphate-solubilizing microorganisms (PSM) have been seen as best eco-friendly means for P nutrition of crop. Although, several bacterial (pseudomonads and bacilli) and fungal strains (Aspergilli and Penicillium) have been identified as PSM their performance under in situ conditions is not reliable and therefore needs to be improved by using either genetically modified strains or co-inoculation techniques. This review focuses on the diversity of PSM, mechanism of P solubilization, role of various phosphatases, impact of various factors on P solubilization, the present and future scenario of their use and potential for application of this knowledge in managing a sustainable environmental system.