Effects of N fertilizer reduction combined with straw biochar application on the yield, Si, and N nutrition of double-cropping rice.

Nitrogen (N) and silicon (Si) are important nutritional elements for rice. However, excessive N fertili-zer application and the ignorance of Si fertilizer are common in practice. Straw biochar is rich in Si, which can be used as a potential Si fertilizer.

[Impacts of biochar and phosphorus application on soil phosphorus availability and soybean phosphorus uptake].

Biochar is beneficial to soil phosphorus (P) availability and crop growth, but the effects vary greatly across different soil types. We investigated the effects of rice straw biochar (4% of total mass) and P application (0, 30, and 90 kg P·hm) on soil P availability, phosphomonoesterase activity, and soybean P uptake by using lateritic red soil (pH 4.91) and cinnamon soil (pH 7.

Regulating effects of silicon on Cd-accumulation and stress-resistant responding in rice seedling.

Silicon (Si) application could significantly alleviate the toxic effects of cadmium (Cd) on the growth and development of rice. Here, we examined the regulatory effects of Si on Cd accumulation and stress response in rice seedlings through a hydroponic root separation test. The results showed that the biomass of rice seedlings decreased significantly under Cd stress, while the addition of Si could alleviate such negative effect.

[Effects of nitrogen fertilizer reduction and biochar application on paddy soil nutrient and nitrogen uptake of rice].

We explored the impacts of nitrogen (N) reduction and biochar application on soil fertility and nutrient uptake of rice in early and late seasons of 2018 with a field experiment. There were six treatments, including control (no N application, CK), conventional N application (N), 20% N reduction (N), 20% N reduction plus biochar application (N+BC), 40% N reduction (N), 40% N reduction plus biochar application (N+BC). Our results showed that 20% and 40% N reduction and/or with biochar application did not affect soil pH, organic matter, total N, total phosphorous (P), total potassium (K), ammonium N, available P and K in comparison with N treatment.

Relative distribution of Cd adsorption mechanisms on biochars derived from rice straw and sewage sludge.

Qualitative and quantitative characterization of Cd adsorption mechanisms was performed with rice-straw and sewage-sludge biochars produced at different temperature (300-700 °C), respectively. The pH effect, adsorption kinetics and isotherms were investigated, and chemical analyses of Cd-loaded biochars were conducted by SEM-EDS, XRD, FTIR and Boehm titration. This demonstrated that rice-straw biochars (RSBs) have greater adsorption capacities for Cd than sewage-sludge biochars (SSBs), which was mainly due to precipitation and cation exchange mechanisms, with their contribution proportion to total adsorption from 76.

Silicon-Mediated Enhancement of Heavy Metal Tolerance in Rice at Different Growth Stages.

Silicon (Si) plays important roles in alleviating heavy metal stress in rice plants. Here we investigated the physiological response of rice at different growth stages under the silicon-induced mitigation of cadmium (Cd) and zinc (Zn) toxicity. Si treatment increased the dry weight of shoots and roots and reduced the Cd and Zn concentrations in roots, stems, leaves and grains.

Quantitative contribution of Cd adsorption mechanisms by chicken-manure-derived biochars.

This study investigated the efficiency and mechanisms of Cd removal by chicken-manure biochar produced at different temperatures. Adsorption kinetics, isotherms, thermodynamic, and desorption were examined, and the biochars before and after adsorption were analyzed by SEM-EDS, FTIR, Boehm titration, and XRD. Kinetics of adsorption were better described by pseudo-second-order kinetic model than pseudo-first-order kinetic and intraparticle diffusion model under different initial Cd concentrations of 20, 50, and 100 mg L.

Heavy metal bioaccumulation and cation release by growing Bacillus cereus RC-1 under culture conditions.

In an effort to explore the detoxifying mechanisms of B. cereus RC-1 under heavy metal stress, the bioaccumulation by growing cells under varying range of pH, culture time and initial metal concentration were investigated from a perspective of cation release. The maximum removal efficiencies were 16.

[Interspecific relationship and Si, N nutrition of rice in rice-water spinach intercropping system.].

Intercropping is a sound eco-agriculture model, but aquatic crops (e.g., rice) intercropping is seldom researched.