Effects of Reducing Application Amount of Base Fertilizer and Increasing Application Time of Leaf Fertilizer on Corn Yield

This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way for corn. On the basis of protecting environment, the economic benefits will be also increased. The results showed that the corn yield was increased with the increase of application amount of base fertilizer, and was also increased with the increase of application time of leaf fertilizer.For each time of spaying of leaf fertilizer, the corn yield was increased 258-592.5kg/hm^2 with increase amplitude ranging from 2.3%-5.6%.

Effects of Nitrogen Application Time on Caryopsis Development and Grain Quality of Rice Variety Yangdao 6

A pot experiment was conducted to study the effects of different nitrogen application time （during the tillering or the booting stages） with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6. The increased nitrogen fertilizer （urea）, especially applied during the booting stage, could evidently increase the milled rice rate, head rice rate and protein content in rice grains compared with the control （no nitrogen application）, and decrease chalky grain rate and amylose content. Moreover, the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages, especially during the booting stage. During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents, but not obviously for the amylopectin content in rice grain. Increased topdressing of nitrogen fertilizer, especially applied during the booting stage, had significant effect on the development and structures of amyloplasts and proteinoplasts. That is, it could change the distribution, number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen, Compared with the control the arrangements of amyloplasts and proteinoplasts were closer, with more numbers, higher density and less interspaces each ohter. Furthermore, most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.

Effect of different fertilization time after human chorionic gonadotropin injection on fertilization outcome of patients in vitro fertilizationembryo transfer

Objective:To explore the effect of different fertilization time after human chorionic gonadotropin(HCG)injection on the outcome of fertilization in vitro fertilization-embryo transfer(IVF-ET).Methods:One thousand one hundred and forty IVF-ET cycles from January 2016 to August 2018 were analyzed retrospectively.According to the different fertilization time after injection of HCG divided into four groups:Group A(38.0 h~39.0 h),Group B(39.1 h~40.0 h),Group C(40.1 h~41.0 h),and Group D(41.1 h~42.0 h).The normal fertilization rate,the normal cleavage rate,the embryo utilization rate,the high-quality embryo rate,the clinical pregnancy rate,the implantation rate,and the spontaneous abortion rate were analyzed among the groups.Then we investigated the effect of different promotion methods on the outcome of fertilization during the optimal fertilization time.Results:There was no significant difference in 2PN cleavage rate,available embryo rate,clinical pregnancy rate,implantation rate and abortion rate among the four groups(P>0.05).The high-quality embryo rate in Group D(44.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate in Group D(71.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate(78.1%)of antagonist group was significantly higher than other groups(P<0.05).Conclusion:The different fertilization time after HCG injection have effects on high-quality embryo rate and normal fertilization rate of patients in IVF-ET.The appropriate fertilization time of patients in IVF-ET was 41 h~42 h after HCG injection in our reproductive center,improved the clinical pregnancy rate and reduced the early abortion rate.The GnRH-ant protocol is superior to other protocol in IVF-ET.

Yield and Grain Quality Response of Spring Wheat Varieties to Irrigation and Fertility Management

Experiments were conducted in 2020 and 2021 in North Dakota to determine the effects of foliar and soil applied fertilizers, variety and irrigation on yield and grain quality of spring wheat. Foliar application of N did not consistently increase yield and protein indicating the soil N levels were adequate to optimize yield. The variety Bolles had higher protein content than Faller. Zinc (Zn) content in the grain was greatest when applied at either flowering or post anthesis. It was also found to be correlated with grain protein content. Yield and grain protein content were negatively related. There was no consistent effect of phosphorous or Zn when applied to the soil on yield, protein, gluten, or Zn content in the grain. Zinc concentration in the grain was significantly correlated with the protein, gluten and P content of the grain. The timing of Zn application was critical to the success of translocating Zn to the grain. Grain Zn concentration increased with most late season foliar Zn applications to both varieties indicating potential for enriching spring wheat nutrient content through production management practices already common in areas that grow spring wheat.

Effects of Organic and Chemical Fertilizations and Microbe Inoculation on Physiology and Growth of Sweet Corn Plants

A pot culture experiment was carried out in a glasshouse to compare the physiology and growth of sweet corn plants (Zea mays L. cv. Honey Bantam) grown under organic and chemical fertilizations with or without microbial inoculation (MI). The organic fertilizer used was fermented mainly using rice bran and oil mill sludge, and the MI was a liquid product containing many beneficial microbes such as lactic acid bacteria, yeast, photosynthetic bacteria and actinomycetes. The application amounts of the organic fertilizer and chemical fertilizers were based on the same rate of nitrogen, phosphorus and potassium. Sweet corn plants fertilized with organic materials inoculated with beneficial microbes grew better than those without inoculation. There were no significant differences in physiology and growth of the sweet corn plants between treatments of chemical fertilizers with and without MI. Among the organic fertilization treatments, only the sweet corn plants with organic fertilizer and MI applied 4 weeks before sowing had similar photosynthetic capacityj total dry matter yield and ear yield to those with chemical fertilizers. Sweet corn plants in other organic fertilization treatments were weaker in physiology and growth than those in chemical fertilization treatments. There was no significant variance among chemical fertilization treatments at different time. It is concluded from this research that this organic fertilizer would be more effective if it was inoculated with the beneficial microbes. Early application of the organic fertilizer with beneficial microbes before sowing was recommended to make the nutrients available before the rapid growth at the early stage and obtain a yield similar to or higher than that with chemical fertilizations.

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING SYSTEMS: ANALYSIS WITH A TOY MODEL

A simple‘toy’model of productivity and nitrogen and phosphorus cycling was used to evaluate how the increasing temporal variation in precipitation that is predicted(and observed)to occur as a consequence of greenhouse-gasinduced climate change will affect crop yields and losses of reactive N that can cause environmental damage and affect human health.The model predicted that as temporal variability in precipitation increased it progressively reduced yields and increased losses of reactive N by disrupting the synchrony between N supply and plant N uptake.Also,increases in the temporal variation of precipitation increased the frequency of floods and droughts.Predictions of this model indicate that climate-change-driven increases in temporal variation in precipitation in rainfed agricultural ecosystems will make it difficult to sustain cropping systems that are both high-yielding and have small environmental and human-health footprints.