Effect of Fertilizer Diammonium Phosphate on Liver,Kidney and Muscle 5-Nucleotidase Activity of Fresh Water Teleost Fish Clarias batrachus

The toxic effect of fertilizer Diammonium phosphate resulted in alterations of 5'-Nucleotidase activity of tissues liver, kidney and muscles offish C. batrachus at varying intervals and exposures. Alterations in 5'-Nuclcotidase activity of body organs gave an idea of the toxicity caused by the fertilizer. Thus the enzyme 5'-Nucleotidase can be used to monitor the pollution in aquatic ecosystem.

The development road of ammonium phosphate fertilizer in China

Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia.At present,there are a variety of products,such as slurry monoammonium phosphate(MAP),diammonium phosphate(DAP),industrial grade MAP,water soluble MAP,water soluble ammonium polyphosphate(APP)and so on.After more than 60 years of development,China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong.The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore.The continuous,stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China.The development of new ammonium phosphate fertilizer products,such as industrial grade MAP,water soluble MAP,water soluble APP,provides technical support for the transformation and upgrading of phosphorus chemical enterprises.In this paper,the production methods,the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.

Maize response to nitrogen and phosphorus starter fertilisation in mineral-fertilised or manured systems

Phosphorus(P)is an essential nutrient for maize production,but in temperate areas the P uptake during early growing stages can be limited due to low soil temperature,even though the soil was tested high in P.The objective of this study was to assess the effects of nitrogen and phosphorous(NP)starter fertilisation during early growth stages and its carryover until maize harvest,in mineral-fertilised or manured systems.A field experiment was carried out in north-west Italy during the 2019 and 2020 growing seasons.The trial compared sub-surface placement of NP(diammonium phosphate)or N alone(ammonium nitrate)in bands close to the maize seed furrows,in differing long-term(LT)fertilisation managements:two doses of urea(Min-L and Min-H),two doses of bovine slurry(Slu-L and Slu-H)or two doses of farmyard manure(Fym-L and Fym-H).The two rates,low(L)and high(H),corresponded to 170 and250 kg N ha^(-1)year^(-1) respectively.Compared to N fertilisation,NP starter fertilisation improved early maize growth assessed by leaf area index(LAI)and shoot dry weight(SDW)in all systems.The effects differed between the two years(2019:LAI+63%,SDW+67%;2020:LAI+36%,SDW+38%),as 2019was cool during the first growth.Higher LAI and SDW values were confirmed at crop flowering in the mineral-fertilised systems only.As shoot growth was enhanced by NP starter fertilisation,anthesis occurred 1 day earlier in all systems.However,a response to NP starter fertilisation at harvest was recorded in mineral-fertilised systems only(+1.3 and+3.2 t ha^(-1) in Min-L and Min-H,respectively).The uptake of P,used as a true indicator of soil nutrient availability,increased with increasing soil Olsen P until 39 mg kg^(-1).These results suggest that soil test thresholds should be revised for points above which P fertilisation should be suspended.

Effects of Phosphate-Solubilizing Bacteria, Rock Phosphate and Chemical Fertilizers on Maize-Wheat Cropping Cycle and Economics

A two-year field study was conducted to test the effects of two phosphate-solubilizing bacteria(PSB), Pantoea cypripedii(PSB-3)and Pseudomonas plecoglossicida(PSB-5), inoculated singly or together with rock phosphate(RP) fertilization on maize and wheat cropping cycle by comparing with chemical P fertilizer(diammonium phosphate, DAP), mainly in the crop yield, soil fertility and economic returns. Inoculation of PSB together with RP fertilization increased the crop growth in terms of shoot height, shoot and root dry biomass, grain yield and total P uptake in both maize and wheat crops compared to the other treatments. Soil fertility in the context of available P, enzyme activities and PSB population in both maize and wheat crops was significantly improved with PSB inoculation together with RP fertilization compared to DAP treatment. The combined use of PSB inoculation and RP fertilization was more economical due to minimal cost and maximum returns. These results suggested that PSB inoculation along with RP fertilization would be an appropriate substitute for chemical phosphate fertilizer application in sustainable agriculture systems.

Highly efficient one-pot synthesis of dihydropyran heterocycles

Diammonium hydrogen phosphate and potassium carbonate-catalyzed one-pot synthesis of 1,4- phenylene-bis（2-amino-4H-pyran-3-carbonitrile and 2-amino-4-aryl-4H-pyran-3-carbonitrile deriva- tives has been achieved by a three-component cyclocondensation of aldehydes, malononitrile, and different nucleophiles in aqueous medium in high yields.