腐植酸对灰漠土棉田土壤无机磷形态的影响

石灰性土壤按常规法施用磷肥,土壤有效磷固定严重,磷肥利用率较低。在新疆典型灰漠土棉田上进行田间试验,通过常规施肥基础上施用不同量腐植酸,研究棉花不同生育期距地表不同深度及距棉株不同距离土壤有效磷及无机磷含量变化、各形态无机磷间动态转化以及施用腐植酸对棉花产量的影响。结果表明：对于典型灰漠土棉田,施用腐植酸能增加耕层土壤速效磷含量,并且随腐植酸用量的增加而增加,腐植酸能起到使土壤稳定持续供应土壤速效磷作用;     

石灰性灰潮土水稻施磷效应及利用率

以通州区石灰性灰潮土为供试土壤,研究了不同施磷水平对土壤速效磷含量及水稻产量的影响,测定了水稻不同施磷水平下磷肥的利用率。结果表明,在中等含磷的土壤上,石灰性灰潮土的磷肥系数为1.72,磷肥临界值为6.0 mg/kg;水稻合理施用磷肥能显著增产,但产量只在一定的施磷水平下随着施磷量的增加而增加,其667 m2最经济施磷量为3.8 kg,最高产量施磷量为9.4 kg。磷肥利用率则随施磷量的增加而逐渐下降,平均利用率为8.5%。     

冬小麦和玉米轮作体系下过磷酸钙和磷酸二铵施用效果比较

在山东潮土进行田间试验,研究过磷酸钙和磷酸二铵施用对冬小麦-玉米轮作体系下作物磷吸收和土壤无机磷形态组成的影响。结果表明:施用磷肥处理小麦、玉米产量高于不施磷肥处理,磷肥种类与用量处理之间没有显著差异;过磷酸钙和磷酸二铵两种磷肥处理土壤不同形态无机磷含量之间差异不明显;P2O5 90和150kg/hm2过磷酸钙和磷酸二铵施用效果相当,因此磷肥施用量可以适当减少。     

从土壤中磷的空间分布特征探讨提高磷肥及土壤磷有效性的新途径

分析论证了我国北方石灰性土壤上磷空间分布严重不均的特征及其原因。并从植物根系的空间分布及吸磷特性等方面论述了土壤磷空间分布不均对植物营养及生长的影响。并针对上述状况提出提高土壤磷及磷肥有效性及利用率的新途径。     

硝酸磷肥在西瓜上的应用效果

硝酸磷肥是一种氮磷复合肥,主要成分是磷酸二钙、硝酸铵、磷酸一铵,次要成分有硝酸钙、磷酸二铵和石膏等。氮素形态包括铵态氮和硝态氮,两者各占1/2,磷素中非水溶性磷约占磷含量的1/2。硝酸磷肥在北方石灰性土壤上对多种作物都有明显的增产效果。为了探讨其在早春小拱棚西瓜上肥料效应及增产效果,我站布置了在双膜小拱棚西瓜上的肥效试验。1　材料与方法1·1　供试土壤试验地块土壤肥力中等,上茬为水稻,排灌条件良好,试验土壤基本理化性状见表1。表1　供试土壤主要理化性状土壤层次/cmpH有机质/(g·kg1)w(N全)/%碱解氮/(mg·kg1)速效P…     

我国农业生产对磷肥的需求现状及展望

从培肥土壤、维持土壤供磷水平和归还作物收获物带走的磷等 3个方面对我国目前和 2 0 10年前后的磷肥需求情况进行了论述。目前我国化学磷肥的年需求量约 10 0 0万吨 P2 O5 ,到 2 0 10年前后我国化学磷肥的年需求量仍为 10 0 0万吨 P2 O5 左右 ,提出我国磷肥产业结构的调整应当积极发展磷酸一铵、磷酸二铵和三元复合肥 ,稳定钙镁磷肥的生产 ,适当压缩过磷酸钙的生产     

基于设施番茄需磷规律的磷肥施用技术规程

设施蔬菜生产体系磷肥用量大、利用率低,土壤磷素淋溶风险高.以设施番茄种植体系为例,划分土壤磷水平指数,明确作物磷肥需求规律,集成启动磷肥技术、磷肥与土壤性质匹配技术、水肥一体化技术及稻壳替代粪肥技术,建立基于根际过程调控的磷肥施用技术,并对该技术的操作性提出了相应的规范,旨在降低磷肥盲目投入,提高磷肥效率,实现设施蔬菜...     

长效缓释磷酸二铵对土壤氮、磷转化及春玉米产量的影响

为探明长效缓释磷酸二铵对土壤中氮、磷的转化及春玉米产量的影响效果,分别进行了土壤硝态氮转化影响试验、15N示踪试验(盆栽)、春小麦根际pH对土壤速效磷的影响试验及春玉米产量影响试验。结果表明:在常规磷酸二铵中添加质量分数0.6%～0.9%的组合控氮促磷抑制剂(HLS)可有效提高氮和磷的利用率,在气候条件相同的情况下可提高作物产量,同时对硝化细菌有抑制作用,可减少氮损失38.7%。     

有机结合态磷肥对土壤微生物及磷酸酶的影响

土壤培养和盆栽试验结果表明：与无机磷肥相比,有机结合态磷肥能够大幅提高土壤微生物数量和土壤磷酸酶含量;有机结合态磷原产物与磷矿粉配合的有机结合态磷肥对提高土壤微生物量的效果最好,比无机磷肥提高23倍,对提高土壤磷酸酶含量的效果也最好,比无机磷肥提高约6倍;有机结合态磷原产物与缓释氮配合的效果次之,但与前者差异幅度不大.有机结合态磷肥具有降低土壤pH的效果,对pH较高的石灰性土壤效果良好,在pH低的红壤上应选用磷矿粉与有机结合态磷原产物复合的肥料效果较好.     

利用同位素技术对不同磷肥的土壤评价

在云南土壤中为了评价不同磷肥的农业效果,用肥料进行细菌土壤研究,测定磷的固定及吸附,在温室条件下,采用同位素技术等进行盆栽试验。     

Controlling phosphorus fixation in calcareous soils by using coated diammonium phosphate

In this paper, phosphorus fixation in calcareous soils is controlled by means of rosin-coated diammonium phosphate pellets, with several rates of phosphorus release. Four soils from arid regions in the Spanish south-east were chosen and separately treated with one of the following fertilizers: superphosphate (SP) or diammonium phosphate (DAP) coated with 0, 10 or 22% rosin with a dosage of 1000 Kg P/ha. After treatment, the soils were incubated for 8 months, in the course of which samples were taken to evaluate the evolution of P availability by means of the electroultrafiltration (EUF) technique.The results obtained show that the use of DAP with a 22% coating enables phosphorus fixation in calcareous soils to be controlled. The coating was sufficiently stable to last for the time it takes the crop to grow.     

饲料磷酸盐联产复混肥磷素原料的开发与应用

利用饲料磷酸盐生产中联产的磷素基础肥料生产不同配方的复混肥,并与利用磷酸二铵（ＤＡＰ）、磷酸一铵（ＭＡＰ）、过磷酸钙（ＳＳＰ）、重钙（ＴＳＰ）、硝酸磷肥（ＮＰ）提供磷素生产的复混肥进行经济性、实用性的比较。磷素基础肥料ｗ（Ｃ－Ｐ２Ｏ５）≥３３％;ｗ（Ｎ）≥３％;外观为白色粉末。     

Phosphate availability in calcareous Vertisols and Inceptisols in relation to fertilizer type and soil properties

The availability to plants of fertilizer phosphorus (P) applied to soil, as measured by chemical extraction, is used to estimate P fertilizer needs. We studied the availability of P, applied as monocalcium phosphate (MCP) powder, ordinary superphosphate (OSP) granules and diammonium phosphate (DAP) granules in 24 calcareous Vertisols and Inceptisols of Andalusia, Spain, by using laboratory incubation techniques. The soils differed widely in their P adsorption- and Ca-phosphate precipitation-related properties. For MCP, availability (defined as the proportion of added P that is recovered by extraction with NaHCO₃ or is isotopically exchangeable) decreased markedly with incubation time and increasing addition rate. The mean recoveries after 180 d of incubation at field capacity at a rate of 246 mg P kg^–1 soil were 17% for Olsen P, 38% for Colwell P, and 16% for isotopically exchangeable P (IEP). Increasing the application rate to 2460 mg kg^–1 resulted in recoveries of 6% for Olsen P, 25% for Colwell P, and 4% for IEP. While IEP-based recovery was not significantly correlated to any soil property, that based on Olsen P (and, to a lesser extent, Colwell P) decreased sharply with increase in the ratio of clay (or Fe oxides) to total (or active) calcium carbonate equivalent. Accordingly, Olsen P might overestimate P availability in those soils relatively rich in carbonate and poor in clay and Fe oxides. On the other hand, recovery of applied P from soils containing more clay and Fe oxides, by a sequential extraction (with H₂O, two 0.5M NaHCO₃ treatments, 0.5M HCl), was lower than 100%, thereby suggesting phosphate occlusion by Fe oxides or clay.Availability of the fertilizers tested 90 d after application was found to decrease in the following order: MCP powder (rate, 246 mg kg^–1) > DAP granules (rate, 547 mg kg^–1) > MCP powder (rate, 738 mg kg^–1) > OSP granules (rate, 308 mg kg^–1). Differences between fertilizers tended to increase with increasing carbonate content in the soil. This may have been due to precipitation of Ca phosphates caused by the presence of Ca in the fertilizer and the high Ca- supplying capacity of the more calcareous soils.     

Agronomical evaluation of phosphate fertilizer as a nutrient source of phosphorus for crops: Isotopic procedure

The agronomic effectiveness of P fertilizers, as sources of phosphorus for crops, was evaluated using the quantities, P_f, of phosphorus taken up byLolium perenne grown on 14 soils during greenhouse experiments in pot cultures. The P_f quantities were determined using³²P-labelled fertilizers. Data were analysed using a new concept: the Isotopic Relative Agronomic Effectiveness (IRAE). The IRAE value was defined as the ratio of the P_f quantity, taken up by a crop, of a tested fertilizer over the P_f quantity, taken up by a crop, of a fertilizer used as standard. In our experiments diammonium phosphate (DAP) was used as standard P fertilizer and two rock phosphates, the North Carolina rock phosphate (NCPR) and a calcium-iron-aluminium phosphate (Phospal), were tested. As a linear relationship between P_f(NCPR) quantities and P_f(DAP) quantities was obtained, with r² = 0.95, when the application rates increased from 15 mgP (kg soil)^–1 to 200 mgP (kg soil)^–1, it is conciuded that IRAE values for a given fertilizer, other than the standard fertilizer, could be determined with a single rate of application. As regards soil pH in the range 4.7 to 8.2 the IRAE_NCPR is related to soil pH by a curvilinear relationship: log IRAE_NCPR = –(0.44) pH + 4.05 with r² = 0.89. The average of IRAE_phospal values was 0.15 with a standard error = 7% irrespective of soil pH. Then a logarithmic relationship was obtained between IRAE values of the two tested fertilizers and their water P-solubility determined at the soil pH where they were applied.     

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 experi-enced 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,pro-vides 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.     

Does long contact with the soil improve the efficiency of rock phosphate? Results of isotopic studies

The effect of incubation on the fate of phosphorus in four phosphatic fertilizers (diammonium phosphate and three rock phosphates) applied to four weakly acid to acid soils was studied. Percent utilisation of fertilizer P by the crop was measured by isotopic labelling and the level and quality of available soil P following addition of fertilizer was measured by the isotopic dilution kinetics method. Percent utilisation of fertilizer P decreased as time of contact between fertilizer and soil increased. The quantity of available soil P increased immediately after applying fertilizer but then decreased. The efficiency of P from rock phosphate was not increased by application long before sowing the crop. From practical viewpoint it is important to apply P fertilizer as near as possible to the time of planting in order to reduce the negative effects of P fixation by the soil.     

The effects of nitrogen fertilizer form on the plant availability of phosphate from soil,phosphate rock and mono-calcium phosphate

A glasshouse trial using lettuce as the test crop, and laboratory incubations were used to evaluate the influence of various nitrogen fertilizers on the availability of phosphate from an unfertilized loamy sand soil and from the same soil fertilized with Sechura phosphate rock or monocalcium phosphate. The order in which nitrogen fertilizer form increased plant yield and P uptake from soil alone and from soil fertilized with the rock was ammonium sulphate > sulphurised urea > ammonium nitrate > urea > potassium nitrate. For each rock application (both 30 and 60 mg/pot) and for soil alone, increased P uptake by the plant correlated well with decreased soil pH. In soil fertilized with the soluble P form, monocalcium phosphate, the form of the nitrogen fertilizer had little effect on plant P uptake. Subsequent laboratory incubation studies showed that increased dissolution of soil-P or Sechura phosphate rock did not occur until acidity, generated by nitrification or sulphur oxidation of the fertilizer materials, had lowered soil pH to below 5.5. A sequential phosphate fractionation procedure was used to show that in soils treated with the acidifying nitrogen fertilizers, ammonium sulphate and urea, there was considerable release of Sechura phosphate rock P to the soil, amounting to 42% and 27% of the original rock P added, respectively.     

An evaluation of the agronomic potential of partially acidulated rock phosphates in calcareous soil

The agronomic potential of four partially acidulated rock phosphates (PARP) made from a moderate reactive phosphate rock at 30 or 60 percent acidulation either by sulfuric acid alone or by combination of sulfuric and phosphoric acids was compared with that of monocalcium phosphate (MCP) and ground rock phosphate (RP) on a calcareous soil (Typic Hapluquent, pH 8.5) in greenhouse. Dry weight and P accumulation of successive cuttings of ryegrass shoots were used to evaluate the relative agronomic potential of these fertilizers. Results indicated that PARPs of higher water-soluble P content had similar immediate effectiveness as MCP at two earlier cuttings, however, they produced significantly less total dry matter than MCP did in overall six successive cuttings. PARPs were constantly inferior to MCP in terms of P uptake by plant in all the six cuttings. When compared to RP, on the other hand, PARPs had markedly higher relative effectiveness. RP itself affected neither the dry matter production nor the P uptake by plant as compared to control treatment.Fractionation of residual inorganic P in the soil samples at two time intervals during plant growth indicated that MCP-P mainly transformed to dicalcium phosphate and octacalcium phosphate, and to a less extent to Fe and Al associated P. These forms of P had significant correlation with P accumulation by plant. Raw RP did not subject to transformation after applied to the soil regardless the duration of culture time. No obvious dissolution of unreacted RP in PARP materials was detected. Plant dry matter production and P uptake were mainly correlated with water-soluble P added with the fertilizers. It is suggested from the experiment that although partial acidulation could substantially improved the effectiveness of rock phosphate and the immediate effect of the fertilizer was competitive with MCP, application of PARP to calcareous soils is only of short-term benefits; in a long run this fertilizer is not considered as a desirable source of P in calcareous soils since the unacidulated part in the fertilizer was unable to be solubilized in the alkaline conditions.     

The effect of direct application of phosphate rock on increasing crop yield and improving properties of red soil

Field experiments, designed to evaluate the effect of direct application of phosphate rock, were carried out on red soil (Ultisol) uplands at three different places. The results indicated: (1) for the first year's crop, the rapeseed yields with phosphate rock treatment and triple superphosphate treatment were almost identical when their rate of phosphorus application was the same; (2) when the same level of phosphorus fertilizer was applied, the residual effect of phosphate rock was better than that of triple superphosphate, and the residual effect of all phosphorus fertilizers on winter crop yields increased with the increase of the amount of Phosphorus applied; (3) with the application of phosphate rock, the pH value, the amount of available phosphorus and exchangeable Ca and Mg of soils went up, whereas the content of active Al in soils decreased. Therefore, the direct application of phosphate rock to red soil also has an important role in improving soil properties.The project was financially supported by American Phosphate Foundation, PPI/PPIC and National Natural Science Foundation of China.