Prediction of phosphate requirements of Swedish turnips from soil phosphate values

Yields from 199 field experiments, extending over about 15 seasons and covering six soil groups in northeast Scotland, were used to calculate correlation coefficients between the responses of Swedish turnips to 120 1b P₂O₅/acre and readily soluble phosphate values for the soils, determined by six methods. There were marked effects of soil parent material and drainage on the correlations, which ranged from ?0.05 to ?0.74. the Morgan and bicarbonate methods were inferior to the NH₄F-HCl, Truog, acetic and lactate methods; the last method was usually the best. By fitting a Mitscherlich equation to the yields the optimum economic phosphate dressings were calculated for four combinations of fertiliser and crop prices. the average profit from these was about 30 shillings/acre greater than from using the mean optimum rate for the soil group or from using a standard rate of 120 1b P₂O₅. Calculations and adjustments tested so far have shown no convincing benefit from using the soil values to recommend phosphate dressings for individual soils. Neither inclusion of other soil properties nor use of the logarithms of the soil phosphate values in multiple regressions produced any appreciable improvement in response predictions. The main reason for the generally rather poor correlations seems to be variations in site characteristics and agricultural factors, rather than soil chemical and textural properties, coupled with the fact that the optimum rates are not well defined. the present indications are that the main practical usefulness of the soil P values is in monitoring of the phosphate status to guide rotational manuring and ensure that adequate dressings can be given for sensitive crops, rather than in the precise prediction of optimum dressings for individual fields.     

酸碱度对紫色甘薯花色素稳定性影响的研究

研究了不同pH对紫色甘薯花色素稳定性的影响。结果表明,酸性条件对花色素的影响不大,且结构稳定;高温和碱性条件能加速花色素的损失,即使回到原来的酸性状态,也难以恢复;碱处理后花色素的吸光度大幅度下降且吸收峰发生偏移,表明花色素的结构可能受到破坏。      

The effect of size of sub-sample on mineral analysis values of apple fruits

Apple fruits were divided into opposite sectors of different sizes, and the mineral analyses of the sectors were compared with whole fruit values. Opposite sectors as small 8-12% of whole fruit weight were found to be as representative as larger sectors. There was no evidence of either a constant or a proportional bias arising as a result of sub-sampling. Sub-sampling variation was greater for Ca than for N, P, K and Mg.     

The effect of selected phosphate emulsifying salts on viscoelastic properties of processed cheese

The aim of this study was to investigate the effect of selected phosphate emulsifying salts (Na₃PO₄, Na₂HPO₄, Na₄P₂O₇, Na₂H₂P₂O₇, Na₅P₃O₁₀, sodium polyphosphate) and their selected mixtures (sodium polyphosphate + Na₂HPO₄; sodium polyphosphate + Na₄P₂O₇) on the viscoelastic properties of model processed cheese (dry matter - 40 g/100 g; fat in dry matter - 50 g/100 g). Viscoelastic properties of model samples stored at 6 ± 2 °C were investigated by dynamic oscillation rheometry (plate-plate geometry; frequency range 0.1-50.0 Hz; temperature 20 °C). Processed cheese manufactured with different phosphates showed various pH values and different viscoelastic properties. The firmness of samples increased due to use of particular types of tested phosphates. Their influence on cheese firmness increased in the following order: orthophosphate < polyphosphate < diphosphate < triphosphate. The increasing content of polyphosphate (up to 50%) in the binary mixture of polyphosphate and orthophosphate or polyphosphate and diphosphate caused the increase of firmness of model samples. The content of polyphosphates above 50% in the binary mixture led to decrease of firmness of model processed cheese.     

Preventing phosphorus losses during perchloric acid digestion of sodium bicarbonate soil extracts

Between 10 and 40% of P was lost during perchloric acid digestion of NaHCO₃ soil extracts for measurement of organic P. This observation was confirmed by ³²P tracer experiments. Addition of MgCl² prevented P loss, reduced variability of replicate determinations and ensured virtually 100% recovery of P added to NaHCO₃ solution and NaHCO₃ soil extracts before digestion. Losses were due both to P volatilisation and conversion of P to forms other than ortho-P in the digestion mixture.     

The effect on egg production of adding sodium bicarbonate and potassium carbonate to a practical-type layer's diet

Eighty laying hens (40 Hisex white, 40 Hisex brown) were given, for ten 28-day periods, a control diet and four experimental diets in which the relationship between Na, K and Cl (Na+K? Cl) expressed as mEq kg^?1 diet was elevated by adding increasing amounts of NaHCO₃ and K₂CO₃. Increasing the (Na+K? Cl) mEq kg^?1 diet had no significant effect on any of the parameters measured but the breed x diet interaction significantly affected mean egg weight.     

磷酸盐对乳化型香肠品质的影响研究

本试验对肉制品中常用的持水剂(焦磷酸钠、三聚磷酸钠和六偏磷酸钠)进行三因素三水平的正交试验L9(34),测定了肉制品的持水性、水分活度、pH值以及质构参数。结果显示:三聚磷酸钠显著地影响肉制品的持水性(p0.1);六偏磷酸钠显著地影响肉制品的质构(p0.1);复配的磷酸盐类对水分活度和pH值虽然有一定的影响,但不显著(p0.1)。     

Phosphate soil tests and their suitability to assess the phosphate status of soil

Some phosphate soil tests (P-tests) are evaluated for their suitability to assess the phosphate status (P-status) of contrasting soils. A P-test at best only provides a relative estimate of the soil P-status, which may be thought of as the ability of a soil to release P either to a crop, or more specifically to a given plant root for a given period under optimum conditions with respect to all other growth factors. A P-test gives no direct information on the crop response to added P. The P-tests were evaluated on the basis of data from 29 published papers where the anion exchange resin method was among the P-tests used, and where plant P-uptake in pot experiments had been used as the evaluation basis. The evaluations ranked the P-tests in three groups: best group: anion-exchange resin method, intermediate group: water, and sodium bicarbonate methods, worst group: all ‘acid’ methods: acetate buffer, lactate buffer, citric acid, Bray-1, Truog and Bondorff methods.     

The effect of pig slurry applied to a soil surface on the composition of the soil atmosphere

Intensive livestock production and labour-saving methods of husbandry require the storage and subsequent disposal of large volumes of slurry on land. The effect of pig slurry, applied to a soil surface, on the composition of the soil atmosphere was investigated using laboratory soil columns. When the effect of slurry was compared with equivalent amounts of glucose, results showed that while both energy sources increased microbial activity, slurry also sealed soil pores, slowing gaseous diffusion rates and delaying the return of the composition of the soil atmosphere to that approaching air. Repeated slurry applications completely sealed the soil surface and oxygen in the soil atmosphere was rapidly depleted. Ethylene, capable of harmfully affecting root-growth, was produced in the anaerobic soil. The fine solids fraction (less than 250 μm particle diameter) of slurry was most effective at blocking soil pores to gaseous diffusion.     

Carbonate and magnesium interactive effect on calcium phosphate precipitation

Precipitation of Ca phosphates, an important process in controlling P stability and activity in P-fertilized soils and P-rich wastewater, is often affected by other components. The purpose of this study was to document interactive effects of CO3(2-) and Mg2+ on Ca phosphate precipitation under conditions simulating (i) dairy manure-amended soil leachate (system I; pH 7.1) and (ii) P recovery from flushed dairy manure wastewater (system II; pH 9.2). Hydroxyapatite (HAP) and more soluble amorphous Ca phosphate (ACP) were formed in the control solutions of system I and system II, respectively. Carbonate only slightly affected the crystallinity of the precipitate, but significantly reduced the precipitation rate via CO3(2-) competition for PO4(3-) (system I) or preemptive CaCO3 precipitation (system II). Magnesium severely inhibited both precipitate crystallinity and precipitation rate, allowing formation of ACP in both systems, presumably due to Mg2+ incorporation into the Ca phosphate structure to form Mg2+ -substituted structure that crystallized to whitlockite upon heating. Coexistence of CO32- and Mg2+ in system I showed a synergistic inhibitory effect, compared to their individual presence, probably because both CO3(2-) and Mg2+ were incorporated into the precipitate. However, in system II, the individual inhibitory effect of CO3(2-) or Mg2+ was eliminated when both were present. The likely mechanism involves formation of aqueous MgCO3 (aq) which reduces free CO3(2-) and Mg2+ activities, resulting in less preemptive CaCO3 formation and enhanced Ca phosphate precipitation.     

The effect of the fore-crop upon winter wheat milling and baking values

The aim of the research was the assessment of the milling and bak-ing value of wheat cultivated after various fore-crops. Spring barley, rape, maize and pea were applied as fore-crops. It has been established that wheat cultivated after spring barley was characterised by the worst technological value. The largest amount of flour was obtained from wheat grain cultivated after maize and rape. Maize and rape used as fore-crops proved to have a favourable effect upon baking value of the flour.     

The effect of basil (Ocimum basilicum L.) on soil organic matter biodegradation and other soil chemical properties

The effects of basil (Ocimum basilicum L.) on soil organic matter biodegradation, nutritional mineral elements and bacterial colonies were studied in the laboratory. The air‐dried basil plant tissues incorporated at five different rates (0, 1, 2, 3, and 4 g per 50 g of soil) resulted in increases in organic carbon mineralization, mineral nitrogen forms in organic phosphorus and available potassium. The level of available forms of manganese and zinc was increased at all the rates of added basil whereas copper was increased at the two upper rates. Also, the addition of basil resulted in a decrease in soil bacterial colonies. The results of this study indicated that the basil could be used as a cover crop for suppressing weed or pathogens in organic soils, with a positive effect on soil productivity. In addition, the incorporation of basil in soil could reduce the number of bacterial colonies. Copyright © 2007 Society of Chemical Industry     

延边地区植烟土壤微生物根际效应分析

在自然生长条件下,用平板-稀释分离培养法研究了延边地区烟叶质量差异较大的3种类型植烟土壤细菌、真菌、放线菌和6种生理类群微生物数量在烟草生育期内的变化动态。结果表明:延边地区植烟土壤微生物根际效应明显。微生物总量R/S值变化范围在1.19-3.07之间,细菌、真菌和放线菌R/S值变化范围分别是:1.21-3.12、1.37-4.36、0.73-4.71。在烟草生育期内,真菌和放线菌R/S值变幅较大,细菌R/S值变幅相对较小。微生物根际效应在3种类型土壤间存在显著差异,暗棕壤根际效应大于黑砂土和白浆土。氨化细菌、硝化、亚硝化细菌和好气性纤维素分解菌表现出明显的正向根际效应,而好气性固氮菌和钾细菌根际效应受土壤类型和烟株生育期影响呈现正、负两方面的根际效应。结论:在3种类型土壤中,暗棕壤烟株微生物根际效应最明显,根际土微生物多样性、均匀度增加,优势集中度下降,根系微生态环境稳定性增强,更有利于烟株生长发育,这可能是暗棕壤烟叶质量优于黑砂土和白浆土的原因之一。     

An effect of suint on sheep wool impedance and heat resistance values

ABSTRACT

The phenomenon of impedance finds an application in many areas of science; however, no studies relate to wool. Thus, the aim of the study was an examination of an effect of from the presence of suint layer on sheep wool fibers on impedance and heat resistance values. Electrical characteristics (impedance [Ω]) and heat resistance were compared in terms of wool washing effect. The impedance of wool samples was tested in the frequency range of 10 Hz to 1 MHz. In order to measure electrical characteristics and heat resistance values, five samples of greasy wool were collected from different sheep breeds, standardized by weight. After the analyses, the samples were washed and reexamined. The results showed significant differences in the impedance between the greasy and washed wool samples in each of the tested breed (p > 0.05). The suint layer reduces the impedance level, which was also confirmed by a heat resistance test results demonstrating that absence of suint layer on wool fibers significantly reduced this feature value (p > 0.05). This was also reflected in the weight differences between the examined wool samples before and after their washing.     

乳杆菌及不同pH值对黄曲霉生长与产毒的影响

为探讨植物乳杆菌及不同PH值对黄曲霉生长与产毒的影响,将植物乳杆菌与黄曲霉孢子同时加入到MRS肉汤和先厌氧培养植物乳杆菌后再加入黄曲霉孢子;以乳酸将LTB培养基的初始PH值调整为3．0,4．0和5．0,以PH值为6．8为对照组,在LTB培养基中接种黄曲霉孢子悬液。上述试验均在28℃培养15d,在培养的第3、6、9、12和15天测定培养液中的PH值,黄曲霉素素B1和黄曲霉菌丝重量。结果显示：植物乳杆菌可显抑制黄曲霉生长（P＜0．05）,同时检测不到黄曲霉毒素B1。随着LTB培养液中PH值的降低,黄曲霉毒素B1的量增加,在PH3．0组,差异有极显性（P＜0．01）,各组间黄曲霉素菌丝量未见显性差异,结果表明：植物乳杆菌可显抑制黄曲霉生长与产毒。在PH值3．0－5．0范围内,乳酸可以刺激黄曲霉毒素B1的产生。     

pH对白砂糖转化糖浆色值的影响

色值是转化糖浆的一个重要质量指标。它直接影响到绵白糖的质量,本文比较了不同水解pH值及中和pH值对转化糖浆制备工程色值的影响,并选择了转化糖浆制备过程的最佳pH值。     

The effect of orchard soil management on the uptake of nitrogen by established apple trees

Nitrogen-15 was supplied as K¹⁵NO₃ to mature Cox/M.26 apple trees grown in conventional wide herbicide strips, with overall herbicide or with complete grass cover. Uptake was measured, following placement, either at 10 cm depth within the tree rows or at 10 or 25 cm depth in the alleys between the rows. Uptake of ₁₅N in the strip treatment was always much greater from the strip than from the grassed alley, while with the overall herbicide trees, uptake was highest from the tree row in June but from the alley in August. With overall grass, uptake was highest from the alley. Management treatments did not affect the total N content of the leaves, so results were similar whether expressed on an atom % or pg μg g^?1 DW basis. In the herbicide strip treatment, application of fertiliser nitrogen at rates between 0 and 126 kg ha^?1 had little effect on either the amount or the pattern of ¹⁵N uptake. Recovery of added ¹⁵N tracer by the trees during the year of treatment varied from 2 to 25% depending upon treatment, position and depth of injection. Absorption of ¹⁵N appeared to be greater in mid-summer than in spring or autumn. Pattern of N uptake was affected by interaction between soil water status, periodicity of root growth and total N demand.