Response of Rice Harvest Index to Different Water and Nitrogen Management Modes in the Black Soil Region of Northeast China

Understanding the methods leading to rice yield increase is vital for sustainable agricultural development. Improving the harvest index (HI) is an important way to increase rice yield. To explore the effects of different water and nitrogen management modes on the rice HI in the black soil region of Northeast China, a field experiment was conducted in 2019 (Y1) and 2020 (Y2). Two irrigation methods, conventional flooding irrigation (FI) and controlled irrigation (CI), were established in the experiment, and four nitrogen application levels (0 kg/ha, 85 kg/ha, 110 kg/ha, and 135 kg/ha) were set during the entire growth period, named N0, N1, N2, and N3. The dry matter weight and the rice yield at the maturity stage were determined, and the HI was then calculated. The results showed that different irrigation modes and nitrogen application levels had significant effects on the rice HI. Under different irrigation modes with the same nitrogen application level during the two years, the comparison regular of HI was consistent. In Y1 and Y2, the HI of FN0 was 3.36% and 5.02% higher than that of CN0 (p < 0.05), and the HI of CN1 was 0.31% and 2.43% higher than that of FN1 (p > 0.05). The HI under CI was significantly higher than that under FI under N2 and N3 (p < 0.05), the HI of CN2 was 4.21% and 4.97% higher than that of FN2, and the HI of FN3 was 13.12% and 20.34% higher than that of CN3. In addition, during the two-year experiment, the HI first increased and then decreased with an increase in the nitrogen application rate under FI and CI. Under the FI treatments, the HI of N1 was the highest, and that of N2 was the highest under the CI treatments. A variance analysis showed that the irrigation pattern and nitrogen application level had significant interactions on the rice HI (p < 0.01), and the appropriate water and N management mode could increase rice the HI by 26.89%. The experimental results showed that the HI of the 110 kg/ha nitrogen application rate under CI was the highest, reaching 0.574 and 0.572, respectively, in two years. This study provides a data reference and theoretical support for realizing water savings, nitrogen reduction, and sustainable agricultural development in the black soil region of Northeast China.

In vitro Regeneration of Picralima nitida (Stapf). T. Durand & H. using Zygotic Embryo

Disinfected mature seed embryos of Picralima nitida, were cultured in MS medium supplemented with different concentrations and combinations of 2,4-D, BAP and NAA to determine an efficient protocol for in vitro propagation. Nine culture media made of combination of different components were used in a factorial design with three replications. Results showed up to 80 ± 4% disinfection rate with combination of triton x- 100 (0.2%) and sodium hypochlorite (30%). Embryo germination was highest on control medium. Rooting was higher (2±1 roots per embryo) after 4 weeks on control medium and on BAP supplemented medium at 0.8 μM while the longest root (1.5±0.5 cm) was observed on 2,4-D supplemented medium at 1.8 μM. Black soil was suitable for leaf formation (4 ± 2 leaves) and shoot elongation (2±1 cm) after 8 weeks in acclimatisation. These results show efficient disinfection, regeneration and acclimatisation of Picralima nitida. Plant Tissue Cult. & Biotech. 31(2): 143-151, 2021 (December)

Hormonal biochemical monitoring at bull-producers of different breeds in the conditions of the Central Black Economic District

Purpose: To conduct a comprehensive monitoring of bulls of different breeds in the summer in a comparative perspective to the study of protein-lipid and mineral metabolism, as well as to determine hormonal status on the content of endogenous hormones: testosterone, estradiol, cortisol and serum thyroxine per day taking seed.Materials and methods. For the first time in a Chernozem region of the Russian Federation (Voronezh region) was carried out comprehensive monitoring of bulls of red-motley Holstein (n = 16), Red-and-White (n = 8) and Simmental (n = 6) rocks in the same time of year (summer) of the protein-lipid and mineral metabolism, as well as the level of endogenous hormone (testosterone, estradiol, cortisol, thyroxine) and their cholesterol precursor in comparative aspect, immediately after taking the seed. Age range bulls ranged from 2 to 11 years. General monitoring was conducted on 23 indices of blood serum 3 rocks. The studies were conducted by modern methods, using modern equipment and reagents.Results. At Red Pied Holsteins an increase of total protein 100.45 g / L versus 92 g / l in normal (above the norm of 9.2%, as compared with red and White breed at the level of 11.3%). A similar increase in concentration in the blood of Holstein bulls red-White breed recorded on globulins, 68.87 g / l to 63 g / l in normal (above the norm of 9.3%), and with respect to the red-and-White breed 17, 6%. Also notes the high content of AST bulls red-motley Holstein against the red-and-White 18%, but within the reference range. Condition protein and lipid metabolism in sires only differed in content of creatinine, which amounted to 165.04 micromol / l against 163 mmol / l in normal, 1.6% higher as compared to the red and white breed this index was higher 18.7%. According to the content of testosterone highest rate was observed in bulls red-White breed 54.73 ± 9.51 nmol / l, is 10.2% more than in bulls red checkered-Holstein and 12.45% compared with Simmental breed. Similarly, in terms of serum cortisol - 355.60 ± 39.2 nmol / l in the red-bulls White breed that more than 2-fold compared with bulls Red Pied Holstein and Simmental. The difference is statistically significant at P ≤ 0,01. According to the content of estradiol relatively low levels recorded in the bulls of red-motley breed - 0.265 nmol / L vs. 0.301 nmol / L in red bulls-motley Holstein, and 0.332 nmol / L - Simmental, is lower by 13.6% and 25 , 3%, respectively.Conclusion. It was found that substantially all of the studied parameters in bulls 3 breeds are at reference values, and this gives grounds to assume that all of these breeds are well adapted to the conditions of Black Soil.

Effect of forecrop on yield of spring durum wheat and soil potassium in chernozems of southern steppe zone in Southern Urals during long-term research

The goal of the study was to determine the infl nce of forecrops on spring durum wheat productivity and content of soil potassium in monoculture, double-cropping and six-year crop rotation at two types of nutrient statuses. The information obtained as a result of long-term experiments is of great interest, since systematic determination of nutrient elements in soil gives a correct assessment of the effect of the longterm use of fertilizers on soil fertility. Content of available forms of potassium in soil under spring durum wheat depending on different forecrops and nutrient statuses was studied. The best forecrops for durum wheat in 31-year experiments were black, soil-protecting and green fallows. The yield of durum wheat after black fallow was 1.20 t/ha under fertilization and 1.27 t/ha without using fertilizers. Vegetative mass of cropped fallow ploughed into soil and use of mineral fertilizers led to an increase in content of soil potassium. The use of mineral fertilizers has a positive effect on yield of durum wheat; the yield increase was 0.10 t/ha after soil protecting fallow, 0.11 t/ha after common wheat and 0.13 t/ha after winter rye. Content of soil potassium was higher in six-year crop rotation and it increased durum wheat productivity compared to double-cropping and monoculture.