Riyuan CHEN,Guangfu LIU,Weilei ZHONG,Wenxiang SUN,Liang ZHANG,Zhaoping HU,Xinzhu LI,Jianqiu CHEN*

1.Kingenta Ecological Engineering Group Co.,Ltd.,276700 Linshu,China;

2.Key Laboratory of Plant Nutrition and New Fertilizer R&D,Ministry of Agriculture,276700 Linshu,China;

3.National Engineering Technology Research Center For SCRF,276700 Linshu,China

Responsible editor:Lin FANG Responsible proofreader:Xiaoyan WU

Phosphate is one of the essential nutrition elements to crops,and the influence is only second to nitrogen[1],so the lack of phosphorus has become an important factor to limite crop growth and yield[2].The phosphorus application is one of the effective ways to increase production of crops.However,ordinary fertilizer applied into the soil is easy to be fixed or lost with the movement of aqueous solution in soil,which resulted in the use ratio of phosphatic fertilizer in seasonal crops was only 5% to 15%.Even if included the after-effects,the use ratio was less than 25%[3].As well as long-term and large application of phosphate fertilizers,many environmental problems appeared[4-5].In recent years,domestic and foreign experts dedicated to breeding crop varieties which could efficiently absorb phosphorus,and hoped to improve the use ratio of phosphatic fertilizer relied on crop’s own absorption ability[6-7].Depending on crop’s own potential could not achieve soil fertility improvement,sustainable use,high yield and stable yield of grain.

Ammonium polyphosphate is a kind of polyphosphate contained nitrogen and phosphorus,and the molecular formula is (NH4)n+2PnO3n+1.When n is within the range of 10-20,it is water soluble,and n of agricultural ammonium polyphosphate usually is within the range of 518; when n is greater than 20,it is insolubility[8].Agricultural ammonium polyphosphate had gradually applied to the production of compound fertilizer and liquid fertilizer,especially widely used in developed countries.But now it only has a small amount of production in China,and not formed the goods to sell.The research of the application of ammonium polyphosphate on crops was rarely reported.Seedling stage is a critical and sensitive period for phosphorus absorption.Phosphorus absorption in the seedling stage occupied 2/3 of that in the whole growth period[9].Based on this,in this experiment,corn was selected as the tested materials to study the effect of ammonium polyphosphate,diammonium phosphate and the different proportion of this two fertilizer on the growth and development,phosphorus absorption and accumulation and zinc absorption in the seedling stage of corn,in order to provide a basis for the promotion of ammonium polyphosphate.

Materials and Methods

Materials

Corn variety Zheng Dan 958 was selected as the test materials.Uniform size of corn seeds were selected and sowed on May 7th2012.After the seeds sprouted,the water content of pot soil in the whole growth period was 75% to 85% of field maximum waterholding capacity by maintained by using the method of quality weight.When 2 to 3 true leaves of the seedlings fully expanded,the final singling carried out on May 27thand the number was 3 per pot.The text was finished on July 6th.

The soil type of test was gravel black sand which was collected from Linyi city.Soil indexes as follows:7.6 of pH,10.22 g/kg of organic matter,0.78 g/kg of total nitrogen,5.5 mg/kg of rapid available phosphorus,120 mg/kg of rapidly available potassium,8.85 mg/kg of available zinc in the soil.

Ammonium polyphosphate (including 10% of N,34% of P2O5) used in this test was prepared by National slow-release fertilizer Engineering Technology Research Center.Diammonium phosphate (including 18%of N,46% of P2O5),ammonium chloride(including 26%of N)and potassium chloride (including 62% of K2O).The grade is chemically pure.

Experimental design

Pot experiment was carried out in the intelligent greenhouse of the National slow-release fertilizer Engineering Technology Research Center.There were five treatments.T1:10 kg of soil+60 mg/kg of P2O5(diammonium phosphate:ammonium polyphosphate = 1:0,available phosphorus ratio); T2:10 kg of soil + 60 mg/kg of P2O5(diammonium phosphate:ammonium polyphosphate = 2:1,available phosphorus ratio); T3:10 kg of soil +60 mg/kg of P2O5(diammonium phosphate:ammonium polyphosphate=1:1,available phosphorus ratio); T4:10 kg of soil+60 mg/kg of P2O5(diammonium phosphate:ammonium polyphosphate = 1:2,available phosphorus ratio); T5:10 kg of soil + 60 mg/kg of P2O5(diammonium phosphate:ammonium polyphosphate = 0:1,available phosphorus ratio).The application rate of N and K2O were 100 mg/kg and 50 mg/kg.Ammonium chloride (containing 26% of N) was selected as the balance of nitrogen,and potassium chloride (including 62% of K2O) was selected as the balance of potassium in this test.The fertilizer application rate of each treatment was showed in table 1.10 kg of soil was mixed with fertilizer and then putted into each flowerpot with the diameter of 28 cm and height of 20 cm.Each treatment with 4 replications.

Determination

Corn growing trend:Measured the height by steel tape and stem diameter by vernier caliper on the 40th day and 60th day after sowed.

Corn biomass:At the end of the test,overground part of corn seedlings were cut off,fixation at 105 ℃for 30 min,dried at 75 ℃and then weighted.The underground part of roots were washed,dried at 75 ℃ and then weighted.

Phosphorus and zinc cumulant in overground part and roots of corn seedlings:Total phosphorus content was determined by H2SO4-H2O2digestion boiling-vanadium molybdenum yellow colorimetric method,and zinc content was determined by HNO3-HClO4digestion boiling-flame atomic spectrophotometer.

Results and Analysis

Effect of different phosphatic fertilizer treatment on corn growing trend

After sowed for 40 d,each treatment group had little effect on the seedlings height and stem diameter,only the seedlings height of T4 treatment was significantly higher than other treatments.After sowed for 60 d,the seedlings height and stem diameter of each treatment appeared different.Among them,the plant height and stem diameter of the treatment groups treated by ammonium polyphosphate were all higher than the groups treated by diammonium phosphate,which the order of plant height was T4＞T3＞T5＞T2＞T1 and the order of stem diameter was T4＞T5＞T3＞T2＞T1 (Table2).The results showed that the addition of ammonium polyphosphate had little effect on the earlier stage of seedlings growth,probably because the nutrient requirements of phosphorus was less in the seedling stage,and the availablephosphorus in the soil could satisfied the needs of corn seedlings.After sowed for 40 d,the available phosphorus content of the soil treated by diammonium phosphate decreased,thereby limited the growth of corn.

Table1 The fertilizer application rate of each treatment

Table2 Effect of different phosphatic fertilizer treatment on corn growing trend

Table3 Effect of different phosphatic fertilizer treatment on dry matter quantity of corn seedlings

Effect of different phosphatic fertilizer treatment on dry matter quantity of corn seedlings

Phosphorus could be easily fixed and ineffective in the soil,so the fertilizer efficiency of a phosphate fertilizer did not depend on its chemical availability but depend on its biological availability[10].The dry matter quantity of crops was the important index of biological availability of phosphorus.Under the application of equivalent phosphorus,the addition of ammonium polyphosphate significantly promoted the growth development of the overground part and roots of corn seedlings,thereby increased the dry matter cumulant and root shoot ratio(Table3).Among them,the dry matter quantity of overground part and roots of T4 treatment group was largest,and the root shoot ratio was also largest.It indicated that the biological availability of ammonium polyphosphate was superior to diammonium phosphate.When the phosphorus content ratio of diammonium phosphate and ammonium polyphosphate was 1:2,the biological availability was highest.

Effect of different phosphatic fertilizer treatment on phosphorus absorption cumulant of overground part of corn seedlings

By statistical analysis about the effect of different phosphatic fertilizer treatment on phosphorus content and phosphorus cumulant of corn seedlings,the results showed that the addition of ammonium polyphosphate had no significant effect on phosphorus content of corn seedlings,but with the increase of application rate of ammonium polyphosphate,the phosphorus content had the trend of increase.It significantly promoted the phosphorus cumulant of overground part of corn seedlings.Compared with T1 treatment group,the phosphorus cumulant of each treatment groups (T2,T3,T4,T5) treated by ammonium polyphosphate increased by 6.11%,11.52%,16.50% and 11.32% respectively.There was significant difference between T3,T4,T5 treatment groups and T1 treatment group (Fig.1).The results showed that the application of ammonium polyphosphate promoted the absorption of phosphorus in seedling stage of corn,which conducive to the growth and development of plants and roots.

Effect of different phosphatic fertilizer treatment on zinc absorption cumulant of corn seedlings

Antagonism action existed between phosphorus and trace elements[11],the improper application of phosphorus would affect the absorption of zinc in corn[12].The results showed that zinc content of overground part and roots of each treatment groups which treated by ammonium polyphosphate was significantly higher than diammonium phosphate treatment (T1),which the zinc content of overground part of T2,T3,T4,T5 treatment groups increased 1.52%6.74% 13.75% and 17.70% respectively,the zinc content of roots of T2,T3,T4,T5 treatment groups increased 1.67% 4.20% 6.79% and 12.51% respectively (Table4).It indicated that the application of ammonium polyphosphate promoted the absorption of zinc in corn seedling.

Discussion

The absorption of phosphorus was less in seedling stage of corn,and the seedling stage was a sensitive period for the reaction of phosphorus nutrition[13].From emergence of seedlings to the 3-4 leaf stage,most of the necessary nutrients was provided by endosperm,but in the latter period,it was mainly provided by soil.The results of some researches indicated that applied water-soluble phosphatic fertilizer to soil for 30 days,the residual was only 27% of the initial fertilizing amount[14].But this time was the criticalperiod of crops for phosphorus demand.The rapidly reduce of available phosphorus was extremely unfavorable to the growth and development of corn in the seedling stage.Ammonium polyphosphate could not be directly absorbed by crops,but only gradually hydrolyzed to orthophosphoric acid and then easy to be absorbed by crops,which ensured the supply of phosphorus in the soil.So ammonium polyphosphate is a long-acting phosphatic fertilizer[8].The results showed that each treatment group applied ammonium polyphosphate had little effect on corn seedling after sowed for 40 days.But with the decline of available phosphorus in the soil,the treatment group not added ammonium polyphosphate or added less would gradually limited the growth of corn.In addition,the growing trend of corn seedling which the polyphosphate all supplied by ammonium polyphosphate was not better than the treatment group which applied 1:1 and 1:2 of diammonium phosphate and ammonium polyphosphat.The possible cause was that the decomposition of ammonium polyphosphate was slowly,which could not ensure adequate supply of available phosphorus to soil.It indicated that single application of ammonium polyphosphate existed the risk of slow decomposition and shortage of phosphorus nutrient.When the combined application of diammonium phosphate and ammonium polyphosphate was 2:1,the treatment group had the best effects.

Table4 Effect of different phosphatic fertilizer treatment on zinc absorption cumulant of corn seedlings

Nutrient content and nutrient accumulation in plant tissues were directly related to the media nutrient supply[15].The test results showed that the application of ammonium polyphosphate had little effect on the phosphorus content of corn seedling,but it promoted the plant growth,so the phosphorus cumulant was significantly higher than diammonium phosphate treatment group,thereby improved the use ratio of phosphorus.The occurrence of phosphorus and zinc antagonism related to the form of phosphorus,which might be related to the change of mechanism of action of soil and zinc caused by applying different forms of phosphorus into the soil[16].The results showed that zinc content of overground part and roots of corn in seedling stage had been significantly improved after the application of ammonium polyphosphate,meanwhile with the greater of the application rate of ammonium polyphosphate,the zinc content was relatively higher in plants.It indicated that ammonium polyphosphate could improved the absorption and utilization of microelement zinc.

Phosphorus could be easily fixed and invalidated in the soil.It also increased the negative charge of soil colloids,which increased the adsorption capacity of soil to zinc,and then decreased available zinc in the soil[17].Therefore,the fertilizer efficiency of a phosphate fertilizer not entirely determined by its own chemistry availability,and the chemical availability was not equal to its bioavailability.In this study,the results showed that the bioavailability of phosphorus improved significantly when the combined application of diammonium phosphate and ammonium polyphosphate was 1:2 by studying the effect of ammonium polyphosphate on the growth of corn seedlings and the absorption of phosphorus and zinc.

[1]LI JY(李繼云),SUN JH(孫建華),LIU QY(劉全友),et al.The effect of roots physiological characteristics and the absorption and utilization efficiency of phosphorus of different wheat varieties on the yields (不同小麥品種的根系生理特性磷的吸收及利用效率對(duì)產(chǎn)量影響的研究)[J].Acta Botanica Boreali-Occidentalia Sinica(西北植物學(xué)報(bào)),2000,20(04):503-510.

[2]Wissuwa M.How do plants achieve tolerance to phosphorus deficiency Small causes with big effects.Plant Physiol,2003,133(4):1947～1958.

[3]BARBER S A,MACKAY.Root growth and potassium uptake by two corn genotypes in the field [J].Fert Res,1986,10:217-231.

[4]LI SX (李生秀).Current status and prospects of plant nutrition and fertilizer discipline (植物營(yíng)養(yǎng)與肥料學(xué)科的現(xiàn)狀與展望)[J].Journal of Plant Nutrition and Fertilizer (植物營(yíng)養(yǎng)與肥料學(xué)報(bào)),1999,5(3):193-205.

[5]GAHOONIA T S,NIEL SEN N E.Root t raits as tools for creating phosphorus efficient crop varieties[J].Plant and Soil,2004,260:47-57.

[6]FOCHES D,CLAASEN N,JUNGK A.Phosphorus efficiency of plant I:External and internal P uptake efficiency of different plant species.Plant Soil,1998,110:101-109.

[7]MARSCHNER H.Role of root growth,arbuscular mycorrhiza,and root exudates for the efficiency in nutrient acquisition.Field Crops Res,1998,56:203-207.

[8]WANG LX (王連祥).Preparation and application of agricultural fertilizer ammonium polyphosphate (農(nóng)用肥料聚磷酸銨的制備與應(yīng)用)[J].Phosphate &Compound Fertilizer(磷肥與復(fù)肥),2008(2):49-50.

[9]HE LZ (何念祖),MENG CF (孟賜福).Plant nutrition principles(植物營(yíng)養(yǎng)原理)[M].Shanghai:Shanghai Science and Technology Press(上海:上海科學(xué)技術(shù)出版社),1987.

[10]MAO XY (毛小云),WU PX (吳平霄),LIAO ZW (廖宗文).Preliminary research of the fertilizer efficiency of several modified phosphate fertilizer(幾種改性磷肥肥效研究初報(bào))[J].studies of soil environment (土壤與環(huán)境),1999(4):318-320.

[11]TENG Y,TIMMER V R.Phosphorusinduced micronutrient disorders in hybrid poplar.Plant and Soil,1990,126(1):19-29.

[12]SINGH,MAHINDRA,SINGH S P.Effects of zinc and phosphorus on absorption of iron and nitrogen by submerged paddy.Soil Science,1983,135(2):71-78.

[13]ZHANG LM(張麗梅),HE LY(賀立源),LI JS ( 李建生),et al.Research of seedling stage screening of phosphorus-resistant material of corn inbred line(玉米自交系耐低磷材料苗期篩選研究)[J].Scientia Agricultura Sinica (中國(guó)農(nóng)業(yè)科學(xué)),2004,37(12):1955-1959.

[14]FENG G (馮固),YANG MQ (楊茂秋),BAI DS (白燈莎),et al.Research of morphology and availability change of phosphorus in calcareous soil with 32P tracer method(用32P 示蹤法研究石灰性土壤中磷素的形態(tài)及有效性變化)[J].Acta Pedologica Sinica (土壤學(xué)報(bào)),1996,33(3):301-307.

[15]WANG Y(王艷),LI XL(李曉林).2000.Research progress of low phosphorus stress adaptation mechanism in different genotypes plants(不同基因型植物低磷脅迫適應(yīng)機(jī)理的研究進(jìn)展).Chinese Journal of Eco-Agriculture (生態(tài)農(nóng)業(yè)研究),2000,8(4):34-36.

[16]ZHAO XL (趙秀蘭),WANG Q (王勤),HU AT(胡靄堂).Research progress of the phosphorus and zinc antagonism(磷鋅頡頏作用研究進(jìn)展)[J].Chinese Journal of Soil Science (土壤通報(bào)),1999(3):42-43.

[17]PARFITT,R L.1978.Anion adsorption by soils and soil materials.Adv.Agron,1978,30:1-50.