RESUMO
Climate changes are one of the biggest threats to food security. Sustainable agriculture, focused on eco-friendly practices for highly efficient food production, enables greater resilience and safety. This study experimented on intercropping and bio-fertilizer application as convenient ecological solutions for crop yield stability and quality. The experiment was conducted during 2018 and 2020 with soybean and common millet sown in three sowing patterns: alternating rows, alternating strips 1 (2 rows of soybean + 2 rows of millet), and alternating strips 2 (2 rows of soybean + 4 rows of millet), as well as sole crops (control), with or without a bio-fertilizer Coveron. Grain yield and nutrient grain yield response were calculated through land equivalent ratio (LER) and element-LER (E-LER), while quality was estimated based on the concentration of antioxidants (phytate phosphorus, total phenolic compounds, and yellow pigment) and elements in grains, including potential bio-availability of essential elements. Results revealed LER values to be >1 for all sowing patterns, with the highest one achieved in alternating strips 1 (1.38) together with a greater level of all antioxidants in millet grain. Intercropping significantly enhanced Fe and Mn accumulation in both crops and simultaneously decreased the concentration of potentially toxic elements (Al, Cr) in millet grain. Potential bio-availability of essential elements, expressed through the ratio between phytic acid and Ca, Mg, Fe, and Zn revealed smaller values in intercropped soybean and millet with the bio-fertilizer. The bio-fertilizer also increased the concentration of some micro-elements in millet grain, classifying it as a highly dependent plant to microbial inoculation. Interaction of intercropping and bio-fertilizer was most pronounced for LER, E-LER, and accumulation of Fe and Mn in grains. These results highlighted the benefits of soybean-common millet intercropping, especially in combination with the bio-fertilizer, in light of enhanced land utilization and nutrient absorption, thus increasing the resilience of soybean and millet under dry land conditions and low-input systems toward stability and food security.
RESUMO
To examine the differences of three improved sowing methods in winter wheat yield and nitrogen efficiency and reveal the characteristics responsible for such differences, we conducted field experiments in the Jinnan area of the western Huang-Huai-Hai wheat region for three consecutive seasons from 2016 to 2019. The three improved sowing methods were wide space sowing (WSS), furrow sowing in moisture soil (FS), and three-dimensional uniform sowing (TDUS), with conventional drilling sowing (CDS) as the control. The results showed that meteorological factors such as accumulated temperature, solar radiation, and precipitation in the growing seasons from 2016 to 2019 showed great intra- and inter-annual variations. Compared with CDS, the improved sowing methods (WSS, FS, and TDUS) enhanced spike number per unit area and increased grain yield in three growing seasons by 18.3%-55.5%, 8.6%-22.2%, and 10.9%-39.5%, respectively. The three methods increased nitrogen uptake efficiency (NEup) by 5.8%-57.1%, pre-flowering nitrogen transfer ratio (Np/Nt) by 3.0%-15.3%, and nitrogen efficiency by 7.9%-35.7%, respectively. We developed a structural equation model (SEM) by integrating meteorological factors and experimental variables. The results showed that the three improved sowing methods could reduce the effects of extreme low temperature on wheat plant population, increase NEup and Np/Nt, and provide sufficient nitrogen supply to the grains of high-spike number wheat population for high yield and high nitrogen efficiency. In summary, our results demonstrated that WSS, FS, and TDUS all improved NEup and Np/Nt in the 2016-2017 season when meteorological conditions were favorable for wheat growth, and enhanced yield components with high SN, leading to high yield and high nitrogen efficiency. In contrast, in both 2017-2018 and 2018-2019 seasons with extremely low temperature and uneven distribution of meteorological conditions, WSS had a higher number of tillers at the jointing stage and enhanced pre-flowering nitrogen uptake and translocation, whereas TDUS had a relatively stable nitrogen uptake rate, leading to a stable grain yield.
Assuntos
Temperatura Baixa , Triticum , Estações do Ano , Transporte Biológico , Grão Comestível , NitrogênioRESUMO
BACKGROUND: Cotton has been increasingly harmed by the mirid bug (Lygus pratensis Linnaeus) in Xinjiang Uyghur Autonomous Region, China. Using trap plants within or around the border of the cotton may be a beneficial management strategy for this pest of cotton. RESULTS: The potential of safflower (Carthamus tinctorius Linn) as a trap plant for managing L. pratensis was evaluated in laboratory and field experiments. Y-tube olfactometer assays demonstrated that L. pratensis was highly attracted to volatiles derived from safflower. Field experiments showed that safflower plots hosted more L. pratensis (adults and nymphs) than cotton plots. Early-sown safflower had more L. pratensis than mid-sown or late-sown safflower, and was more conducive to the settlement and reproduction of L. pratensis. The density of L. pratensis on safflower trap crops in three sowing patterns was significantly higher than on adjacent cotton. The pattern of intercropping safflower trap crops was more effective at reducing densities of L. pratensis on cotton than placing safflower as 'spot' trap crops or peripheral trap crops. However, this result also may be related to the overall area of the safflower trap crops. With regular chemical control of L. pratensis on safflower trap crops, the number of cotton bolls was increased by 10.04%, whereas the rate of boll damage was reduced by 33.44%, compared to cotton without safflower trap crops and insecticide sprays. CONCLUSION: Safflower shows promise as an effective trap crop for L. pratensis, and may contribute to controlling L. pratensis in cotton. © 2020 Society of Chemical Industry.