Effect of Tillage Treatments of Hairy Vetch Residues on Soil Inorganic-N Distributions and Corn Growth in a Subtropical Region

Conservation tillage has many advantages in crop production and weed control management. N-residue of hairy vetch as a green manure cover crop through tillage and no-tillage practices may increase inorganic-N level in soils and contribute to sustainable agriculture. Prior to corn cultivation, hairy vetch was cut after growing in the pots for 103 days. Six treated soils were prepared for no-tillage treatments (SRN, RN, and CN) and for tillage treatments (SRT, RT, and CT), where the soils were treated by shoot and root of hairy vetch residues, only root residues, and without application of hairy vetch as a control, respectively. Seeds of corn (Zea mays L.) were sown and grown for 56 days after sowing. The shoot and root biomasses of corn under no-tillage were higher than those of tillage. Furthermore, the shoot biomass of corn in both SRN and SRT were higher than that in other treatments. The root biomass of corn was higher in upper layers (0–5 cm depth) and deeper layers (>10 cm depth) than in middle layers (5–10 cm depth) of soils. In the upper layer, the NH4-N contents of no-tillage were higher at 9 and 23 DAT than those of tillage. The NH4-N content of the soils for no-tillage in the middle layer and the deeper layer was lower than that of the CT treatment. The NO3-N content of no-tillage in the middle and deeper layers was lower than that of CT at 23 and 65 DAT. N-uptake of corn in both no-tillage and tillage treatments with hairy vetch addition was higher than that of the control

Growth and Nutrient Accumulation of Winged Bean and Velvet Bean as Cover Crops in a Subtropical Region

We examined biomass dry matter and nutrient uptake of live plant parts, leaf area index, and litter of winged bean (Psophocarpus tetragonolobus) and velvet bean (Mucuna pruriens) 12, 18, 24 and 30 weeks after sowing (WAS). The two plants had similar leaf and stem+petiole biomasses. At 30 WAS winged bean had a significantly lower pod yield than velvet bean. Between 18 and 30 WAS, winged bean produced less litter than velvet bean due to differences in growth stages. The total mulch of live parts and litter of winged bean and velvet bean completely covered the ground by 18 and 12 WAS, respectively. Compared to velvet bean, the leaf and stem+petiole of winged bean had a significantly higher N concentration; significantly higher N uptake at 24 and 30 WAS; significantly lower C/N ratio; and significantly higher P, K and Mg concentrations. In winged bean, P uptake was significantly higher in the leaf at 30 WAS and in the stem+petiole at all harvesting times. The total biomass of the leaf, stem+petiole and litter of winged bean was 317–561 g DM m-2, and their N content was 12.3–17.7 g m-2. The total biomass of live parts and litter of winged bean might be sufficient to suppress weeds and increase soil N. Winged bean is an appropriate legume cover crop and green manure due to its longer growing period and superior ground-covering ability and high N input

Morphology Controlled PA11 Bio-Alloys with Excellent Impact Strength

Polyamide 11 (PA11), 100% biobased plastics, and polypropylene (PP) were mixed with a reactive compatibilizer, maleic anhydride modified ethylene–butene rubber copolymer (m-EBR), by a twin-screw extruder, and mechanical properties and morphology of resulting injection molded PP/PA11 bio-alloys were investigated by flexural tests, Charpy notched impact tests, ¹³C NMR, differential scanning calorimetry, X-ray diffraction, field-emission scanning electron microscopy, scanning transmission X-ray microscopy, transmission electron microscopy, and atomic force microscopy. We found that it possible to control the morphology of bioalloys. When the morphology of the bioalloy showed “salami” structure, it achieved superior impact-resistance with high flexural modulus, which are generally not accomplished at the same time. The mechanical properties of the bioalloy were better than those of PP which was used in the car industry. When the bioalloy had a “nano-salami” structure, the impact strength was surprisingly improved. The morphology observations revealed that the reactive compatibilizers were in the interphase between a matrix and a dispersed phase and were in a dispersed subdomain in the dispersed phase. The compatibilizers played a key role in improving impact strength. The bioally will be expected to apply in the car industry and other areas