Study on the Changes of the Major Nutrient Elements During Simple Composting Process of Dry Chicken Manure

[Objectives]This study was conducted to provide a theoretical basis for production and application of chicken manure compost.[Methods]With dry manure as a material,the variations of the major nutrients during simple composting process of dry chicken manure were studied,in order to get the best fermentation method.[Results]Chicken manure should not be preserved wet,but should be preserved after air-drying and fermented before use.Necessary moisture,simple sealing treatment and a certain amount of N element were conducive to simple fermentation of chicken manure.The treatments in which the chicken manure was wrapped around and compacted,added with an appropriate amount of water(50%-60%)and naturally fermented,or was wrapped around and compacted and added with an appropriate amount of water(50%-60%)and 0.2%of urea,were more appropriate for the production directly.[Conclusions]This study provides a theoretical basis for the actual production and application of chicken manure compost.

Determination of Nutrient Contents in the Leaf Litter of <i>Diospyros crassiflora</i>S. (Hiern-FWTA) Plantation in Okwuta-Ibeku, Umuahia, Abia State, Nigeria

Determination of nutrient contents in Diospyros crassiflora leaf litter was carried out in the Forestry Research Institute of Nigeria (FRIN), Okwuta-Ibeku, Umuahia, Abia State, Nigeria in 2016 and 2017. Three 1 m × 1 m trays were randomly positioned for collection of leaf litter production from 4/5 years old Diospyros crassiflora species in each block (10 m × 25 m) within the plantation totaling 1.5 ha. A Randomised Complete Block Design (RCBD) with three replicates was used to study the mean monthly leaf litterfall of Diospyros crassiflora. Leaf litter was collected from each of the three litter trays per block and placed in paper bags every 28th day of each month from January-December in 2016 and in 2017. Fifteen grammes (15 g) of properly mixed and oven-dried samples of D. crassiflora leaf litter were milled and sieved in 1 mm sieve;0.3 g was used to determine nutrient elements and their concentrations. The data obtained from mineral nutrient contents of D. crassiflora leaf litter was analysed using analysis of variance. Result reveals the mean concentrations of nitrogen (1.41 and 1.41 mg·l-1), phosphorus (0.18 and 0.18 mg·l-1), potassium (0.68 and 0.68 mg·l-1), sodium (0.35 and 0.30 mg·l-1), calcium (1.57 and 1.56 mg·l-1), magnesium (0.32 and 0.31 mg·l-1), chlorine (0.25 and 0.24 mg·l-1), Organic carbon (0.03 and 0.03 mg·l-1) and Organic matter (1.17 and 1.18 mg·l-1) etc. in D. crassiflora leaf litter in January-December (2016 and 2017). The study shows almost uniform distribution of mineral elements concentrations in 2016 and 2017.

Effect of Plant Roots on Soil Nutrient Distributions in Shanghai Urban Landscapes

Twenty-seven surface soil samples were collected from four landscape sites in Shanghai, and seven soil profile samples were gathered from the two older sites for evaluation of horizontal and vertical distribution of soil properties to reveal their relationship with plant roots. Results indicated that urban soil had significant heterogeneities. Soil total nitrogen was significantly correlated with organic matter and total potassium was more abundant than total phosphorus. The available contents of iron, manganese, zinc and copper were higher than the standards for plant growth established by Soltanpour. pH and electrical conductivity increased with increasing soil vertical depth, possibly due to leaching, while the nutrients limiting plant growth such as nitrogen, phosphorus, potassium, iron, copper and zinc had more shallow distributions due to absorption by plant roots. However, with the increasing of soil depth, contents of magnesium, sodium, sulfur and chloride increased due to leaching and bio-cycling, which was further shown by the correlation analysis.

田林老山中山两类森林凋落物研究

田林老山中山两类森林凋落物研究梁宏温（广西农学院林学分院，南宁５３０００１）ＳｔｕｄｉｅｓｏｎｔｈｅＬｉｔｔｅｒｆａｌｌｏｆＴｗｏＦｏｒｅｓｔＴｙｐｃｓｉｎＭｉｄ—ＡｌｔｉｔｕｄｅｏｆＬａｏｓｈａｎＭｏｕｎｔａｉｎｉｎＴｉａｎｌｉｎＣｏｕｎｔｙ．￥Ｌ...

Impact of vegetation succession on leaf-litter-soil C:N:P stoichiometry and their intrinsic relationship in the Ziwuling Area of China’s Loess Plateau

Long-term natural vegetation succession plays a substantial role in the accumulation and distribution of plant and soil C:N:P stoichiometry.However,how plant and soil C:N:P relationships or ratios change along with successional stages over a century in the severely eroded areas remain unclear.These were measured over a 100-year natural succession in five successional stages from annual grasses to climax forests.The results show that natural succession had significant effects on carbon(C),nitrogen(N)and phosphorous(P)concentrations in leaf-litter-soil and their ratios in severely eroded areas.Nitrogen concentrations and N:P ratios in leaf and litter increased from annual grasses to the shrub stage and then decreased in the late successional forest stages.Leaf P levels decreased from annual grasses to shrub stages and did not significantly change during late successional stages.Litter P concentration decreased in the early successional stages and increased during late successional stages,with no overall significant change.Soil C and N concentrations and C:N,C:P and N:P ratios increased with successional stages.Soil C and N concentrations decreased with the increasing soil depth.Both were significantly different between any successional stages and controls(cropland)in the upper 10 cm and 10–20 cm soil layers.Leaf N:P ratios may be used to indicate nutrient limitations and this study suggests that plant growth during the grass stages was limited by N,during the shrub stage,by P,and during the forest stages,by both of N and P.In addition,there were close correlations between litter and leaf C:N:P ratios,soil and litter C and N levels,and C:P and N:P ratios.These results show that long-term natural vegetation succession is effective in restoring degraded soil properties and improving soil fertility,and provide insights into C:N:P relationships of leaf,litter and soil influenced by vegetation succession stage.

Functions of Nitrogen,Phosphorus and Potassium in Energy Status and Their Influences on Rice Growth and Development

Nitrogen(N),phosphorus(P)and potassium(K)are important essential nutrients for plant growth and development,but their functions in energy status remains unclear.Here,we grew Nipponbare rice seedlings in a growth chamber for 20 d at 30℃/24℃day/night)under natural sunlight conditions with different nutrient regimes.The results showed that N had the strongest influence on the plant growth and development,followed by P and K.The highest nonstructural carbohydrate content,dry matter weight,net photosynthetic rate(Pn),ATP content,as well as NADH dehydrogenase,cytochrome oxidase and ATPase activities were found in the plants that received sufficient N,P and K.The lowest values of these parameters were detected in the N-deficient plants.Higher dry matter accumulation was observed in the K-deficient than in the P-deficient treatments,but there was no significant difference in the ratio of respiration rate to Pn between these two treatments,suggesting that differences in energy production efficiency may have accounted for this result.This hypothesis was confirmed by higher ATP contents and activities of NADH dehydrogenase,cytochrome oxidase and ATPase in the K-deficient plants than in the P-deficient plants.We therefore inferred different abilities in energy production efficiency among N,P and K in rice seedlings,which determined rice plant growth and development.

REGIONAL GEOCHEMISTRY OF RUBBER PLANTATION IN HAINAN ISLAND,CHINA

Hainan Island is located in the northern periphery of the tropical world.The environment is suitable for a number of tropical economic crops.The content of soil organic matter under rubber plantation is around 10- 20 g kg-1.Cu,Zn,Mn,As,Mg,Ca and K in the soil profile reflect the parent material and the intensive weathering and leaching in the area.Copper has noticeably accumulated in the lower horizon,whereas the concentrations of Ca,Mg and K.in rubber trees are 0.5- 4.9,2.2- 4.3 and 4.6-10.2 g kg-1 respectively.These three elements are mostly distributed in the plant roots and are particularly required during the development of new leaves early in the season.

Impact of metal oxide nanoparticles on cotton(Gossypium hirsutum L.):a physiological perspective

Cotton production substantiated a crucial part in the escalating economic development of many countries.To realize the increasing global demand for cotton,the emphasis should be laid on to improve cotton fiber growth and production.The bioengineered transgenic cotton proved expedient in resolving inadequacies of conventional cotton,but still required improvements to encounter heightened demand of textile industries.One possible solution pertaining to this has been provided by nanoscience in the form of metal or metal oxide nanoparticles.These metal oxide nanoparticles have easy access to the various parts of cotton plants through its transportation system,and thus significantly influence several parameters relative to the growth and production of cotton fiber.This review summarizes the distribution and accumulation of metal oxide nanoparticles in cotton plant and its impact on different plant growth-promoting factors,which resulted in the improved cotton yields.

Co-exposure of sulfur nanoparticles and Cu alleviate Cu stress and toxicity to oilseed rape Brassica napus L.

Experimentswere performed to explore the impact of sulfur nanoparticles(SNPs)on growth,Cu accumulation,and physiological and biochemical responses of oilseed rape(Brassica napus L.)inoculated with 5 mg/L Cu-amended MS medium supplemented with or without 300 mg/L SNPs exposure.Cu exerted severe phytotoxicity and inhibited plant growth.SNPs application enhanced the shoot height,root length,and dry weight of shoot and root by 34.6%,282%,41.7%and 37.1%,respectively,over Cu treatment alone,while the shoot and root Cu contents and Cu-induced lipid perodixation as the malondialdehyde(MDA)levels in shoots and roots were decreased by 37.6%,35%,28.4%and 26.8%.Further,the increases in superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),ascorbate peroxidase(APX),glutathione reductase(GR)and glutathione S-transferase(GST)enzyme activities caused by Cu stress were mitigated in shoots(10.9%–37.1%)and roots(14.6%–35.3%)with SNPs addition.SNPs also positively counteracted the negative effects on shoot K,Ca,P,Mg,Mn,Zn and Fe contents and root K,Ca,Mg and Mn contents from Cu exposure alone,and significantly promoted the nutrients accumulation in plant.Additionally,in comparison with common bulk sulfur particles(BSPs)and sulfate,SNPs showed more positive effects on promoting growth in shoots(6.7%and 19.5%)and roots(10.9%and 15.1%),as well as lowering the shoot Cu content(40.1%and 43.3%)under Cu stress.Thus,SNPs application has potential to be a green and sustainable technology for increasing plant productivity and reducing accumulation of toxic metals in heavy metal polluted soils.

Potential metal-related strategies for prevention and treatment of COVID-19

The coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has posed severe threats to human health,public safety,and the global economy.Metal nutrient elements can directly or indirectly take part in human immune responses,and metal-related drugs have served as antiviral drugs and/or enzyme inhibitors for many years,providing potential solutions to the prevention and treatment of COVID-19.Metal-based drugs are currently under a variety of chemical structures and exhibit wide-range bio activities,demonstrating irreplaceable advantages in pharmacology.This review is an intention to summarize recent progress in the prevention and treatment strategies against COVID-19 from the perspective of metal pharmacology.The current and potential utilization of metal-based drugs is briefly introduced.Specifically,metallohydrogels that have been shown to present superior antiviral activities are stressed in the paper as potential drugs for the treatment of COVID-19.