Search

To address the issues related to the excessive use of nitrogen fertilizer and the low transplanting density in rice, the effects of reduced or increased nitrogen density on rice yield and nitrogen use efficiency were investigated, so as to provide a scientific basis for optimizing the production of rice in the cold region of northeast China. A field experiment was conducted during 2019 to 2020 to evaluate the effects of four cultivation management strategies on rice yield, shoot dry matter, nitrogen (N) accumulation and distribution, and N use efficiency at Hongguang farm, Qianguo County, Jilin Province. The strategies were as follows: no N fertilizer and transplanting density of 1.80×105 hole·hm-2 (N0), application of 235 kg·hm-2 N and transplanting density of 1.80×105 hole·hm- 2 (FP), application of 188 kg·hm-2 N and transplanting density of 2.40×105 hole·hm-2 (SNHD1), and application of 188 kg·hm-2 N and transplanting density of 3.00×105 hole· hm-2 (SNHD2). Compared with FP, SNHD1 and SNHD2 treatment led to significant increase in the number of effective panicles and the overall rice yield. In particular, SNHD1 led to an increase in yield by 7.8% on average over two years. Accumulation of dry matter and N in each growth stage of rice including after full heading were promoted by N reduction and transplanting densification. SNHD1 led to better results than SNHD2. Nonetheless, absorption efficiency, agronomic use efficiency, partial productivity, and nitrogen fertilizer use efficiency of N all increased significantly in both cases compared with the FP treatment. For SNHD1, in particular, increases by 0.3, 6.2, 14.4 kg·kg-1, and 16.4 percent points were evaluated, respectively. FP, SNHD1, and SNHD2 all led to a surplus in the apparent N balance in both years, with the lowest value evaluated for SNHD1. A significant positive correlation among dry matter and N accumulation before and after full heading and grain yield was observed. Moreover, the correlation between dry matter and N accumulation after full heading was higher than that before full heading. The use of reasonable N application rate and transplanting density led to an increase in dry matter and N accumulations during the entire growth period of rice, as well as to an increase in the accumulation ratio after full heading, enhanced yield, and N use efficiency. Overall consideration of rice yield, N uptake and N utilization, the use of 188 kg·hm-2 of N fertilizer and a 2.40×105 hole·hm-2 transplanting density represent the optimal cultivation conditions in the cold region of northeast China. [ABSTRACT FROM AUTHOR]

This study analyzed environmental and economic benefits of 8 types of vegetables in 4 different farms over 3 years. The specific results were as follows:(1)The input-output ratio and carbon footprint of organic production mode was 18.5% and 87.4% of that of pollution-free mode, respectively; (2)Fertilizer and power consumption was the main source of carbon emissions, accounting for 58.76% and 16.67% of total carbon emissions, respectively; (3)There were positive correlations between N fertilizer and both carbon emissions and carbon footprint. In other words, higher use of N fertilizer resulted in higher carbon emissions and carbon footprint; (4) When organic fertilizers use reached 122 352 kg·hm-2, the crop production could reach the maximum under organic mode. Under the mode of pollution-free production, when agricultural chemicals input reached 20 103 yuan·hm-2, leafy vegetable production could reach the maximum. Therefore, to increase production and reduce carbon emissions in the process of vegetable production, the main approach was to use organic mode, increase the quantity of organic fertilizer, instead of the use of inorganic N fertilizer and other agricultural chemicals and establish water-saving irrigation system for electricity efficiency. [ABSTRACT FROM AUTHOR]

Because of its low price and simple operation and maintenance, the three-compartment septic tank toilet has become the main technical mode of the rural toilet revolution in underdeveloped areas. However, there are some widespread misunderstandings about its functional orientation, which will have a negative impact on the correct use of the septic tank, the harmless disposal of manure, and there use of manure. Therefore, this paper traced the development of the septic tank, analyzed its functional orientation under differents anitation patterns, and revealed the historical mission of sanitation and environmental protection of septic tank toilets. On this basis,analysis of the three typical misunderstandings of the current rural toilets in some areas, namely, the problem of common use flush toilets,“pipe collection+（centralized）large septic tank”,“collection+off-site dehydration dry fertilizer”, revealed the need to pay attention to the correct use of septic tanks, and incorporated the septic tank toilet in rural areas into the application of rationalization recommendations. [ABSTRACT FROM AUTHOR]

：This study was conducted in 2018 to determine the correlation between the characteristics of male flower and the pollinated fruits of kiwifruit. Selecting "Xuxiang" as the female parent, pollen from 10 male plants of kiwifruit was used for pollination. The characteristics of different male flowers and hybrid fruit traits were investigated, and the results showed significant differences among pollination combinations in fruit characters. The highest and the lowest fruit setting rate was 56.67%, 3.33%, respectively. The maximum and the minimum fruit weight was 68.53, 32.07 g, respectively. The maximum Vc content was 2.14 mg∙g-1, with a minimum of 1.10 mg∙g-1. The highest and the lowest solid-acid ratio was 68.63, 25.55, respectively. There were significant correlations between male flower and fruit traits. Our results indicated an obvious xenia effect in kiwifruit. The selection of suitable pollinating male plants will improve fruit properties and is important in kiwifruit industry. [ABSTRACT FROM AUTHOR]

In order to examine the ecological effects of planting grass in kiwifruit orchards in Shiyan, Hubei Province, we selected two kiwifruit orchards located in Changpingtang and Gaoling villages as study sites. We assessed the effects of two grass planting methods, namely, artificial and natural grass planting, and selected white clover and ryegrass as artificial grass types. The effects of artificial and natural grass planting on soil nutrients, weed species and quantity, and fruit yield and quality were compared and analyzed. The results showed that compared with natural grass planting, artificial grass planting could effectively reduce the number and quantity of weed species, particularly in response to planting white clover. It also increased the contents of soil organic matter, alkali-hydrolyzed nitrogen, available phosphorus, and available potassium in the two kiwifruit orchards, and reduced the pH value of alkaline soil. Furthermore, of the two artificial grass types assessed, ryegrass was found to have a better effect on reducing soil pH than white clover. However, neither of the grass planting methods had a significant effect with respect to improving soil temperature, or fruit yield and quality, although artificial grass planting was found to significantly increase soil humidity in the Gaoling kiwifruit orchard（P<0.05）. With an extension of planting time, planting ryegrass clearly increased the contents of soil alkali-hydrolyzed nitrogen, available phosphorus, and available potassium. The findings of this study revealed that compared with planting natural grass and white clover, planting ryegrass was more suitable for kiwifruit orchards in Shiyan, Hubei Province. [ABSTRACT FROM AUTHOR]

In order to explore the effects of different residual film amounts on the infiltration performance of soil water, five residual film treatments were conducted：0（T0）, 100（T1）, 200（T2）, 400（T3）, 800 kg·hm-2（T4）with the object of light sierozem in Yinchuan Plain. One-dimensional vertical constant head infiltration method was used to observe soil water movement under different amounts of residual film. We also simulated soil water infiltration process with 4 infiltration models and evaluated their applicability. The results showed that the cumulative infiltration decreased with the increase of the residual amounts. When the infiltration time was 390 min, the cumulative infiltration decreased by 4.7%, 5.8%, 6.3%, 11% for T1~T4 treatments contrast to T0, respectively. The migration distance of dripping wet front in the same time was shorter with the increasing of the residual amounts in the soil. The infiltration time of T0~T4 treatment were 390, 420, 510, 600, 660 min at the end time of infiltration, respectively, which indicated that infiltration time was prolonged with the increasing of residual amounts. The stable infiltration rate of T0~T4 was 0.27, 0.24, 0.21, 0.19, 0.16 mm·min-1, respectively, which indicated infiltration rate decreased with the increasing of residual amounts. The R2 of the fitted infiltration models was as follow：Common experienced model> Kostiakov model>Philip model>Horton model. The common experienced model was more effective than the other models, and it was suitable to describe the soil water infiltration process with residual film. The study indicated that the agricultural residue had a hindering effect on soil water infiltration for light sierozem in Yinchuan Plain, and the influence degree would aggravate with the increase of the residual amounts. [ABSTRACT FROM AUTHOR]