• McKinnon Delacruz posted an update 1 week, 3 days ago

    i-arid area of the Loess Plateau, Northwest China.The intercropping of legume and cereal crops could affect crop roots growth. The relationship among intercropping, root morphology and phosphorus (P) acquisition under different P levels is still unclear. With field experiments and a rhizo-box experiment, we examined the changes of yield, biomass, P acquisition and root morphology of wheat and faba bean under different planting patterns (monocropped wheat, MW; monocropped faba bean, MF; and wheat and faba bean intercropping, W//F) and different P levels. In the rhizo-box experiment, both root weight and root-shoot ratio were increased by 21.2% and 61.5%, respectively, but shoot weight was decreased by 14.6% when wheat intercropped with faba bean. Root P content and P uptake of intercropping wheat (IW) increased by 23.8% and 12.1% when compared to MW. Both shoot and root weight, root-shoot ratio, total root length, and root volume of intercropping faba bean (IF) increased by 16.5%, 47.3%, 24.0%, 3.5%, and 8.4% as compared to MF, respectively, which resulted in higher shoot and root P content and P acquisition of IF. In the field experiment, P uptake by IW decreased by 8.7% at tillering stage, but P acquisition increased by 40.6%, 19.7%, 7.8% and 12.4% at join-ting, heading, filling, and maturity stages as compared to MW. By contrast, P acquisition of IF decreased by 9.8%, 9.0% and 5.2% at flowering, podding, and maturity stages as compared to MF. Partial least squares (PLS) regression analysis showed that root surface area and total volume of wheat and root surface area of faba bean had the greatest contribution to crop P acquisition. Intercropping induced higher root volume and root surface area which resulted in higher P acquisition under low P stress. In conclusion, interspecific interaction amplified the root-soil interface zone and increased P uptake at seedling stage under low P stress, which could contribute to the intercropping advantages at later stage.To understand the effects of deep ploughing during the fallow period and soil moisture-based furrow sowing on the utilization of water and nitrogen in dryland wheat, a field experiment following split-plot design was carried out from 2016 to 2018 in Wenxi County of Shanxi Province, with deep ploughing during the fallow period and no-tillage as main plots and soil moisture-based furrow sowing and drilling sowing as sub-plots. The results showed that, compared with no-tillage treatment, deep ploughing during the fallow period significantly increased soil water storage efficiency (by 38.3%-42.2%), soil water consumption (by 9.2%-13.2%), and nitrogen accumulation in each growth period, which in turn increased the yield by 7.1%-12.0%, annual water use efficiency by 5.5%-14.0%, nitrogen fertilizer absorption efficiency by 4.4%-10.3%, and nitrogen fertilizer partial productivity by 7.1%-12.0%. Compared with the treatment of drilling sowing, the soil moisture-based furrow sowing increased the total water consumption during the growth period (by 2.0%-4.8%) and nitrogen accumulation in each growth period, increased the yield by 6.8%-12.4%, water use efficiency during the growth period by 4.5%-7.2%, nitrogen absorption efficiency by 4.4%-10.3%, nitrogen partial productivity by 6.9%-12.4%. In conclusion, deep ploughing during the fallow period and soil moisture-based furrow sowing in dryland wheat could promote the storage and utilization of natural precipitation, increase plant nitrogen accumulation, and facilitate high wheat yield.To clarify the effects of row spacing and sowing rate on the vertical distribution of canopy PAR, biomass, and grain yield in winter wheat, a field experiment was conducted without increa-sing water and fertilizer input. There were two row spacing modes, R1 (equal spacing, 20 cm+20 cm) and R2(wide and narrow row spacing, 12 cm+12 cm+12 cm+24 cm), and three sowing rates, D1 (low, 120 kg·hm-2), D2 (medium, 157.5 kg·hm-2), D3 (high, 195 kg·hm-2). The canopy photosynthetically active radiation (PAR) interception and utilization rate in different heights, population photosynthetic capacity, biomass, and grain yield were measured during the main growth stages of winter wheat. The results showed that both total PAR interception and upper layer PAR interception of winter wheat canopy under R1 treatment were significantly higher than those in R2 treatment, but those of the middle layer and lower layer were higher in R2 than in R1, and with significant difference in the middle layer. From flowering to maturity, the phosignificantly higher than R1. In summary, the PAR interception in the middle and lower layers of winter wheat canopy was improved by changing row spacing, with positive consequence on the photosynthetic capacity of individual plant and population, PAR utilization and transformation efficiency, which finally increased biomass and grain yield. Therefore, optimizing the field structure and shaping the ideal population photosynthetic structure should pay more attention during the high-yield cultivation of winter wheat. Making full use of light resources per unit land area and excavating the photosynthetic production potential of crops were also critical to achieve high yield and efficiency. In this experiment, the population photosynthetic capacity, photosynthetic effective radiation utilization rate, and yield were the highest under the treatment of R2D2.We investigated the effects of potassium-releasing bacteria on physiological and bioche-mical characteristics of Lycium barbarum (Cultivar Ningqi 1) under salt stress, with an experiment with treatments following randomized block design. The treatments included control (CK), 100 mmol·L-1 NaCl stress (NaCl), 100 mmol·L-1NaCl stress+KSBGY01 bacteria (NaCl-M1), 100 mmol·L-1NaCl stress+KSBGY02 bacteria (NaCl-M2), and 100 mmol·L-1NaCl stress+KSBGY01+KSBGY02 (NaCl-M3). We measued chlorophyll content, polyphenol content, superoxide anion (O2-·) content, hydrogen peroxide (H2O2) content, soluble sugar content, antioxidant enzyme activity and sucrose metabolic enzyme activity of Lycium barbarum seedlings. DMX-5084 molecular weight Results showed that the presence of potassium bacteria increased the values of flavonoids (FLAV), fluorescence excitation than anthocyanins relative index (FERARI), anthocyanins (ANTH-RB), nitrogen balance index (NBI-G), decreased the contents of O2-· and H2O2, and improved soluble sugar content, catalase (CAT) activity, sucrose phosphate synthase (SPS) activity, sucrose synthase (SS) activity and invertase (INV) activity of leaves in Lycium barbarum seedlings under salt stress.