Influence of biochar on improving hydrological and nutrient status of two decomposed soils for yield of medicinal plant - Pinellia ternata

The root tuber of Pinellia ternata has been used as a traditional therapeutic herbal medicine. It is reported to impart beneficial attributes in recovering COVID-19 patients. To meet an increasing demand of P. ternata, this study is intended to investigate the effects of biochar on the soil hydrological and agronomic properties of two decomposed soils (i.e., completely decomposed granite (CDG) and lateritic soil) for the growth of P. ternata. The plant was grown in instrumented pots with different biochar application rate (0%, 3% and 5%) for a period of three months. Peanut shell biochar inclusion in both soils resulted in reduction of soil hydraulic conductivity and increase in soil water retention capacity. These alterations in hydrological properties were attributed to measured change in total porosity, biochar intra pore and hydrophilic functional groups. The macro-nutrient (i.e., N, P, K, Ca, and Mg) concentration of both soils increased substantially, while the pH and cation exchange capacity levels in the amended soils were altered to facilitate optimum growth of P. ternata. The tuber biomass in biochar amended CDG at all amendment rate increases by up to 70%. In case of lateritic soil, the tuber biomass increased by 23% at only 5% biochar application rate. All treatments satisfied the minimum succinic acid concentration required as per pharmacopoeia standard index. The lower tuber biomass exhibits a higher succinic acid concentration regardless of the soil type used to grow P. ternata. The biochar improved the yield and quality of P. ternata in both soils.

Summary of N-star nitrogen recommendations in Arkansas during 2021

Seeking to fine-tune nitrogen (N) application, increase economic returns, and decrease environmental N loss, some Arkansas rice (Oryza sativa L.) producers are turning away from blanket N recommendations based on soil texture and cultivar and using the Nitrogen Soil Test for Rice (N-STaR) to determine their field-specific N rates. In 2010, Roberts et al. correlated years of direct steam distillation (DSD) results obtained from 0- to 18-in. soil samples to plot-scale N response trials across the state to develop a field-specific, soil-based N test for Arkansas rice. After extensive small-plot and field-scale validation, N-STaR is available to Arkansas farmers for both silt loam and clay soils. Samples submitted to the N-STaR Soil Testing Lab in 2021 were summarized by county and soil texture, totaled 21 fields across 9 Arkansas counties, and were from 6 clay and 15 silt loam fields. Depressed sample submissions were again observed likely due to another wet spring and lingering effects of the COVID-19 pandemic. The N-STaR N-rate recommendations for samples were compared to the producer's estimated N rate, the 2021 Recommended Nitrogen Rates and Distribution for Rice Cultivars in Arkansas, and the standard Arkansas N-rate recommendation of 150 lb N/ac for silt loam soils and 180 lb N/ac for clay soils. Each comparison was divided into 3 categories based on a decrease in recommendation, no change in recommended N rate, or an increase in the N rate recommendation. In all 3 comparisons, county, but not soil texture, was a significant factor (P < 0.04) in observed decreases in N recommendation strategies demonstrating variations in the soil's ability to supply N across the state. Further stressing the potential N cost savings opportunities, reductions greater than 30 lb N/ac were recommended by N-STaR in 71%, 50%, and 74% of fields in the standard, estimated, and cultivar comparisons, respectively.

Progress of the karstic-erosive processes of soils in San Jose de las Lajas polje

An update of the karstic morphogenesis in San Jose de las Lajas polje is carried out, with the objective of making a quantitative evaluation of the of karstic-erosive process advance. It is from a baseline of more than three decades in reference localities, in accordance with the conditions of use and management to which soils have been subjected. It demonstrates the effects of intensive anthropogenesis on the Red Ferrallitic soils, as a result of a multifactorial process, conditioned not only by the intrinsic properties of the soil cover and conditions of use, but also dependent on the geological-geomorphological conditions. The application of the Integrating System of Qualitative and Quantitative Methods allowed characterizing the complex influence of the relief in the evolution of the main morphometric parameters of the dolines with losses between 12.33-15.95 t ha-1 year-1. It converted into length units show reductions in the A+B horizons between 0.98-1.20 mm year-1, which exceed the permissible threshold values in terms of erosion proposed by the USLE and the rates of formation of soils derived from limestone rocks in Cuba. It has a marked tendency to increase, which confirm the need for protection and improvement so that their "immunity" to erosion ceases to be a myth and becomes a priority issue for Food Security in the post Covid-19 development programs in Cuba. These soils represent the maximum potential to satisfy the country's current demand for agricultural and livestock productions.