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Role of Microbial Biofilm in Agriculture and Their Impact on Environment
Published in Bakrudeen Ali Ahmed Abdul, Microbial Biofilms, 2020
Asma Rehman, Lutfur Rahman, Ata Ullah, Muhammad Bilal Yazdani, Muhammad Irfan, Waheed S. Khan
The available form of calcium (Ca) to plants is Ca2+ ion, and functionally it is involved in the formation, plasticity, and permeability of cell wall and plasma membrane to maintain integrity exchange of materials. Ca acts as an activator for several enzymes, having a significant role in protein synthesis and carbohydrate transport, and plays a vital role as detoxifying and acid neutralizing agent in combination with other compounds. As a neutralizing agent, it indirectly improves productivity by reducing soil acidity and is essential for the production of seed in peanuts. As a result of calcium deficiency, leaves and root tips of plants become brown in color and finally dies. Further, its shortage may cause secondary effects like soil acidity, plant fragility, and premature fall of buds and blossoms.
AFO/CAFO Siting: Physical Factors
Published in Frank R. Spellman, Nancy E. Whiting, Environmental Management of Concentrated Animal Feeding Operations (CAFOs), 2007
Frank R. Spellman, Nancy E. Whiting
Animal manure releases ammonia gas upon drying Urea content in manure is unstable. As manure dries, the urea breaks down into ammonium. The release of gaseous NH3 from manure can result in ammonia toxicity. Exposure of corn seeds to ammonia during the initial stages of germination can cause significant injury to the development of seedlings. High levels of NH3 and NH4 in the soil interfere with the uptake of the calcium ion, causing plants to exhibit calcium deficiency (Hensler et al., 1970). Part of the ammonium released is adsorbed on the cation exchange sites of the soil, releasing calcium, potassium, and magnesium ions into solution High levels of these ions in the soil solution contribute to an increase in the soluble salt level as well as pH.
Soil
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Calcium-deficient soils are relatively uncommon. Application of lime, a process used to treat acid soils (see Section 15.4), provides a more than adequate calcium supply for plants. However, calcium uptake by plants and leaching by carbonic acid (Reaction 15.4) may produce calcium deficiency in soil. Acid soils may still contain an appreciable level of calcium that, because of competition by hydrogen ion, is not available to plants. Treatment of acid soil to restore the pH to near neutrality generally remedies the calcium deficiency. In alkaline soils, the presence of high levels of sodium, magnesium, and potassium sometimes produces calcium deficiency because these ions compete with calcium for availability to plants.
Diagnosis and recommendation integrated system and nutritional balance index reveal Cd-induced nutritional disorders in Panicum maximum assayed for Cd phytoextraction
Published in Bioremediation Journal, 2020
Flávio Henrique Silveira Rabêlo, José Lavres, Thiago Gentil Ramires, Luís Reynaldo Ferracciú Alleoni
From the data of nutrient concentration (Table 1), it was observed that the concentrations of P, K, S, Cu and Fe in the shoot of P. maximum cv. Massai increased due to Cd exposure and there was no Cd-induced reduction in the concentration of any nutrient. However, DRIS revealed that certain nutrients were in deficient concentrations compared to others (Table 3). There was a strong deficiency of Ca, Mn and Mg when P. maximum cv. Massai was exposed to 0.1 mmol L−1 of Cd, and there was a deficiency of Zn, N and Cu when this genotype was exposed to 0.5 mmol L−1 of Cd (Table 3). Calcium deficiency compromises cell extension and membrane stabilization of plants, which can result in less leaf area (Marschner 2012; Mehrabanjoubani et al. 2015), as recorded in P. maximum cv. Massai exposed to Cd by Rabêlo et al. (2018c). Evidently, Cd toxicity can compromise cell extension per se by inducing the rupture of cell membranes (Loix et al. 2017), but nutrient imbalance induced by toxic elements have an additional detrimental effect on plant growth (Jarrell and Beverly 1981). As an example, Cd can enter into the guard cells in competition with Ca2+ leading to stomatal closure, lower CO2 conductance and inhibition of photosynthesis (Perfus-Barbeoch et al. 2002), and all these effects emerged on exposure of P. maximum cv. Massai to Cd (Rabêlo et al. 2018c).