Evaluation of the Effects of New Environmental Additives Compared to Mineral Fertilizers on the Leaching Characteristics of Some Anions and Cations under Greenhouse Plant Growth of Saline-Sodic Soils

Abstract

Aims: The aim of this study was to determine and monitor the influences of organic and biological additives compared to mineral fertilizers on leaching characteristics of anions and cations, also to know more about the ability of these additives to make complexes with dissolved and toxic salts to decrease soil salinity. Background: Salt-affected soils comprise of saline and sodic soils which differ in origin, physico-chemical properties and the constraints to plant growth. Due to the presence of excess soluble salts (e.g. sodium (Na+) and chlorides (Cl-)). Methods: Ten treatments were established, including two levels of spent grain (environmental organic wastes from the beer industry), S1(10 g of spent grain / kg soil) and S2 ( 20 g of spent grain / kg soil); two levels of compost M1(10 g of compost / kg soil) and M2 ( 20 g of compost / kg soil); mixed M1 with S1 (M1S1); inoculation of Azospirillum brasilense (A1); inoculation A1 with S2 (A1S1); inoculation A1 with M1 (A1M1); 20:20:20 of N, P, and K fertilizers (NPK), and control (CK, without any additives). All treatments were mixed with 30 kg soil pots under greenhouse conditions, corn (Zea mayz L.) seeds were sown in the soil pots. The most relevant nitrogen and salt in soil leachates were collected and analysed every 20 days for 100 days. The soil leachates were collected under plant growth from pots by closed system. Results: The result revealed that organic additives such as A1 and S2 treatments effectively decreased soil pH, soil EC, and reduced NaCl concentration in soil leachates. The Ca2+ and K+ cations in the soil leachates were not stable at high levels of organic additives. Soluble NO3- and NH4+ were significantly lower in A1, S2, and A1S1 treatments than in NPK, M2, and CK treatments. Soil treatment with A1 and S2 significantly improved the soil chemical environment by increasing the Cation Exchange Capacity (CEC) and soluble and exchangeable-K+ and thus limited entry of Na+ into the exchange complex in soil and consists complex with soluble Na+ as sodium humate form. Conclusion: In the final, the highest nitrogen use efficiency with the least NO3- and NH4+ losses in saline-sodic soil was also found in S2 and A1 treatments. Moreover, under this bio-organic fertilization way, NO3- concentrations in soil leachates was outside of danger of damaging the environment. Thus, spent grain with Azospirillum were suggested to be the optimal fertilizer with the lowest nitrogen leaching losses, best yield, quality, and the least groundwater environmental risk under corn (Zea mays L.) organic and bio-organic cultivation comparing with chemical cultivation.

The response of saline-sodic soils to reclamation using biological and organic amendments under arid regions of Egypt

“…The low osmotic effects in the soil treated with SG2 and Az could result from the sodium complex with organic matter as a sodium humate form. These results were agreed with [12]. Also agree with [11,13] found the exchange complexes forming Ca 2+ by exchanging with Na + from the cation exchange complex Na2SO4, MgSO4, and other high-solubility salts illustrate this decrease in EC concentrations.…”

“…Similarly, [10,11] reported increases in Ca 2+ , K +, and Mg 2+ concentrations in soil solution of soil treated with organic amendments. In a laboratory experiment on saline-sodic soil reclamation, the effects of deferent organic amendments on the same soluble cations [12] reported significantly (P > 0.05), the soil additives of spent grain and Azospirillum bacteria might provide supplemental soluble macronutrients such as Ca 2+ , Mg 2+, and K + in leachates of saline-sodic soil.…”

“…The increasing application rate of Az and SG1 was enhanced pH reduction. However, the increase in soil pH may induce the Ca 2+ to become more alkaline and, therefore, more sodic as calcium solubility is suppressed; this was proposed by [12]. In arid and semi-arid climates, the soluble Ca 2+ and Mg 2+ become low, Na + and K + ions accumulate in soil solution when CO3 -2 and HCO3increase [13].…”

The Effective Combination of Humic Acid Phosphate Fertilizer Regulating the Form Transformation of Phosphorus and the Chemical and Microbial Mechanism of Its Phosphorus Availability

“…The application of phosphate fertilizers (such as TSP, SSP, FCMP, DAP, MAP) has been proven to promote crop growth, development, and ultimately to increase yield [4][5][6][7]. However, after the application of phosphate fertilizer, soil buffer capacity decreases, and phosphorus is absorbed by soil colloidal particles and metal ions, gradually forming non-available phosphate that is difficult for crops to absorb and utilize [8,9] because of the poor mobility of phosphorus in soil [10]. At present, the utilization rate of phosphate fertilizer in China is about 10-20% [11].…”

Enhancing Meteorological Drought Modeling Accuracy Using Hybrid Boost Regression Models: A Case Study from the Aegean Region, Türkiye

“…This inherent variability necessitates an intricate and region-based understanding of droughts to deal with their impacts. While the increase in the frequency and severity of extreme weather phenomena can be linked to global warming [4][5][6][7][8], shorterterm events like meteorological and agricultural droughts often exhibit more complex behavior. Thus, it is vital to accurately forecast droughts and establish drought early warning systems for effective planning and resilience [9].…”