Microbiological Indices for Diagnosis of Heavy Metal Contaminated Soils

Heavy metal contamination has gained popularity worldwide due to their persistent nature in the environment, on the top of that non-biodegradable nature makes its accumulation easy to toxic levels. Understanding the nature of contamination has become a major concern before heavy metals deteriorate the quality of soil; to diagnose heavy metal pollution suitable indices are required. Microbial indices gaining importance because of their sensitive nature towards change in surrounding, which is the imperative quality required to select microbes as environmental indicators. Albeit enough literature is present related to this topic but the information is scattered so role of this chapter is imperative. The chapter will be helpful for the reader to provide a thorough understanding of merits and demerits of microbiological indices for heavy metal contaminated and restituted soils. The changes in microbiological indices and their mechanism of response towards heavy metal stress are effectively summarized. Research gap and future needs of microbial diagnosis of heavy metal contaminated soils are discussed

Optimizing the Methods and Schedule of Fertilization Escalated Nutrient Uptake, Nutrient Use Efficiency and Dry Matter Yield of Sugarcane (Saccharum officinarum L.)

A field study was performed at Regional Research Station, Uchani (Karnal) of CCS Haryana Agricultural University, Hisar, India during 2020-21 to ascertain the role of precision nutrient management in enhancing nutrient availability to plants by amending the schedule and method of N and K fertilization in spring planted sugarcane (Saccharum officinarum L.) crop under wide spacing (120 cm). The experiment was devised under split plot design with three replications. The main plot treatments consisted of two methods of fertilizer placement (B1-broadcasting and B2-band placement) while sub plot treatments included four schedules of application of recommended dose of N and K (RDN+RDK) in five splits (T1), six splits (T2), seven splits (T3) and T4 (RDN in three splits, full dose of P and K at planting). All the main and sub plot treatments showed a remarkable influence on nutrient uptake (kg ha-1), partial factor (kg kg-1) productivity, dry matter accumulation (t ha-1) and plant macro-nutrient content. B1 and T1 among main and sub plot treatments respectively lead to greater nutrient uptake, partial factor productivitie of NPK and highest dry matter yield

Selenium Mediated Alterations in Physiology of Wheat under Different Soil Moisture Levels

Soil moisture stress is one of the most serious aspects of climate change. Selenium (Se) is regarded as an essential element for animal health and has been demonstrated to protect plants from a number of abiotic challenges; however, our knowledge of Se-regulated mechanisms for enhancing crop yield is limited. We investigated the effects of exogenous Se supplementation on physiological processes that may impact wheat productivity during soil moisture stress. The plants were grown in plastic containers under screen-house conditions. The experiment was laid out in CRD consisting of three soil moisture regimes, i.e., control (soil moisture content of 12.5 ± 0.05%), moderate (soil moisture content of 8.5 ± 0.05%), and severe moisture stress (soil moisture content of 4.5 ± 0.05%). Selenium was supplied using sodium selenite (Na2SeO3) through soil application before sowing (10 ppm) and foliar application (20 ppm and 40 ppm) at two different growth stages. The foliar spray of Se was applied at the vegetative stage (70 days after planting) and was repeated 3 weeks later, whereas the control consisted of a water spray. The water status, photosynthetic efficiency, and yield were significantly decreased due to the soil’s moisture stress. The exogenous Se application of 40 ppm resulted in decreased negative leaf water potential and improved relative water contents, photosynthetic rate, transpiration rate, and stomatal conductance in comparison to the control (without selenium) under water shortage conditions except the plants treated with soil application of selenium under severe moisture stress at 70 DAS. Subsequently, Se-regulated mechanisms improved 100 seed weight, biological yield, and seed yield per plant. We suggest that Se foliar spray (40 ppm) is a practical and affordable strategy to increase wheat output in arid and semi-arid regions of the world that are experiencing severe water shortages

Selenium Mediated Alterations in Physiology of Wheat under Different Soil Moisture Levels

Soil moisture stress is one of the most serious aspects of climate change. Selenium (Se) is regarded as an essential element for animal health and has been demonstrated to protect plants from a number of abiotic challenges; however, our knowledge of Se-regulated mechanisms for enhancing crop yield is limited. We investigated the effects of exogenous Se supplementation on physiological processes that may impact wheat productivity during soil moisture stress. The plants were grown in plastic containers under screen-house conditions. The experiment was laid out in CRD consisting of three soil moisture regimes, i.e., control (soil moisture content of 12.5 ± 0.05%), moderate (soil moisture content of 8.5 ± 0.05%), and severe moisture stress (soil moisture content of 4.5 ± 0.05%). Selenium was supplied using sodium selenite (Na2SeO3) through soil application before sowing (10 ppm) and foliar application (20 ppm and 40 ppm) at two different growth stages. The foliar spray of Se was applied at the vegetative stage (70 days after planting) and was repeated 3 weeks later, whereas the control consisted of a water spray. The water status, photosynthetic efficiency, and yield were significantly decreased due to the soil’s moisture stress. The exogenous Se application of 40 ppm resulted in decreased negative leaf water potential and improved relative water contents, photosynthetic rate, transpiration rate, and stomatal conductance in comparison to the control (without selenium) under water shortage conditions except the plants treated with soil application of selenium under severe moisture stress at 70 DAS. Subsequently, Se-regulated mechanisms improved 100 seed weight, biological yield, and seed yield per plant. We suggest that Se foliar spray (40 ppm) is a practical and affordable strategy to increase wheat output in arid and semi-arid regions of the world that are experiencing severe water shortages