摘要:

The Diagnosis and Recommendation Integrated System (DRIS) has proven useful in the interpretation of tissue elemental analyses for many crops, and research was undertaken to apply the same method for foliar diagnosis of soybean (Glycine max[L.] Merr.). Using a data bank in excess of 3500 tissue samples, reference values for evaluating the status of soybean with respect to N, P, K, Ca, Mg, Mn, Fe, Cu, Zn, Mo, B and Al were derived. DRIS diagnoses generally agreed with those obtained by the sufficiency range method. In addition, DRIS assessed the nutrient balance in plant tissue, and identified not only the most‐limiting element, but the order in which other elements would likely become limiting. Further, DRIS was able to diagnose plant nutrient needs earlier in the life of the crop than the sufficiency range method (5 weeks compared to 10 weeks), which would allow remedial steps to be taken earlier. Treatments indicated by DRIS to be needed gave greater yield increases than those indicated by the sufficiency range approach. Geographic differences in DRIS norms were identified, and indicate that regional derivation of diagnostic values may be necessary.

ISSN:0010-3624    

DOI:10.1080/00103628609367711

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The absorption and utilization of most elements by plants are strongly influenced by factors other than elemental concentration in the soil solution such as soil pH, organic matter, CEC and interactions with other nutrients. This field study was conducted to determine the response of soybean cultivars with different tolerance to P induced growth disorders to applied P, Zn, and Cu at different soil pH levels. Both Wright (tolerant) and Hutton (sensitive) soybean cultivars showed a significant response to applied Zn. The greatest response was observed for Hutton although Wright had seed yields as great or greater than those for Hutton. Yield of both cultivars was significantly correlated with leaf Zn concentration and the P/Zn ratio. The highest yields for both cultivars were associated with leaf Zn concentrations of approximately 26 μg/g and P/Zn ratios of 115. Applied P did not affect yield or P absorption of either cultivar. Copper fertilization increased Cu concentration in plant tissue by 38% to 58% but did not influence seed yields. Seed yield and Zn absorption of both cultivars was reduced by increased pH with yield decreasing at a faster rate when Zn was not applied than when plants received Zn fertilizer. Copper concentrations in plant tissue were not affected by increased soil pH. Zinc concentration of leaf tissue was also affected by a P‐Zn interaction. Wright contained much greater concentrations of leaf Zn, Fe, Cu, and several other nutrients than did Hutton indicating a greater ability to absorb these elements under conditions of high soil pH and P levels. This ability may account for the difference in tolerance to P induced growth disorders that has been observed between these cultivars. Within each pH treatment, Zn absorption was highly correlated to extractable soil Zn but when soil pH was not taken into account neither DTPA nor Mehlich No. 1 ex‐tractable soil Zn adequately predicted Zn absorption. Better results were obtained by using prediction equations determined by multiple linear regression with extractable soil Zn and pH as the independent variables. These equations accounted for 80% to 95% of the variation in leaf Zn concentration.

ISSN:0010-3624    

DOI:10.1080/00103628609367712

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The crop land in Alaska has increased five‐fold in the past ten years. The state includes a relatively large geographic area and the agricultural soils vary considerably from volcanic ash to loess derived soils. The P‐sorption capacities of the soils also are known to vary widely but little data is available on the nature of soil P and the performance of P extractants on these soils. A laboratory and growth chamber study was conducted to investigate the suitability of seven P extractants for use on Alaska agricultural soils. Ten representative soils were collected from the agricultural regions of Alaska, five were volcanic ash derived and five were loess derived. Response of barley (Hordeum vulgare L. var. ‘Weal') to soil test P‐levels was determined in the growth chamber. Soil P levels were established from P‐isotherm curve data and soil P levels were determined using Morgan, Bray 1, Bray 2, Mehlich 1, Mehlich 2, Mehlich 3, and Olsen extracting reagents.

ISSN:0010-3624    

DOI:10.1080/00103628609367713

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Surface soils from ten soil series representing five great groups were collected from Alaska. These soils were selected from the important agricultural areas covering a wide geographic distribution. These soils can be divided into two distinct groups based on their parent material: loess and volcanic ash. Phosphorus sorption maxima were calculated based on the Langmuir isotherms. The volcanic ash soils (Cryandept and Cryorthods) showed an average P‐sorption maxima of 10,122 mg/kg and loess soils averaged 3,934 mg/kg. Both groups have similar portions of phosphorus in the organic form (19%) and occluded form (8 to 9%). The nonoccluded‐P in the volcanic ash soils and the loess soils was 68% and 43% respectively, and the Calcium‐P was 4% and 29% respectively.

ISSN:0010-3624    

DOI:10.1080/00103628609367714

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A Dionex ion chromatograph was used to measure the anion content of four vegetable species. Separation of the anions by ion chromatography permitted their quantitation by conductivity measurement, following suppression of background (eluant) conductivity by a fiber cation exchanger. Aqueous extracts of pumpkin, tomato, turnip, and lettuce leaves yielded chromatographic profiles with substantial differences in the relative amounts of chloride, phosphate, nitrate, and sulfate. Common to each profile were two additional major anion peaks, which appear to be organic acids. A high degree of precision was achieved in the quantitation of all anions except phosphate. Organics were not found to pose serious problems in these analyses. Some potential interference by proteins extracted from the dried leaf powders was eliminated or controlled by using short (15 min) extraction times, and/or briefly boiling the extracts to denature and remove the proteins.

ISSN:0010-3624    

DOI:10.1080/00103628609367715

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Work reported showed that N‐butyl phosphorothioic triamide (NBPT) is considerably more effective than phenylphosphorodiamidate (PPD) as a soil urease inhibitor and merits consideration as a fertilizer amendment for retarding hydrolysis of urea fertilizer in soil. Studies to determine the factors influencing the effectiveness of NBPT for retardation of urea hydrolysis in soil showed that the inhibitory effect of NBPT on hydrolysis of urea by soil urease increased markedly with the amount of NBPT added and decreased markedly with time and with increase in temperature from 10 to 40°C. They also showed that the ability of NBPT to retard urea hydrolysis in 13 surface soils selected to obtain a wide range in properties was significantly correlated with organic C content (r = ‐0.70**), total N content (r = ‐0.76**), cation‐exchange capacity (r = ‐0.67* ), sand content (r = 0.61*), clay content (r = ‐0.63*),and surface area (r = ‐0.66*), but was not significantly correlated with pH, silt content, urease activity, or CaCO3equivalent. Multiple‐regression analyses indicated that the effectiveness of NBPT for retardation of urea hydrolysis in soil tends to increase with decrease in soil organic‐matter content.

ISSN:0010-3624    

DOI:10.1080/00103628609367716

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In seeking reasons for differences in sensitivity among vegetables to low soil pH and the roles of lime and fertilizers, an experiment was conducted in 1984 with 3 crops: snapbeans (Phaseolus vulgarisL.), tomatoes (Lycopersicon esculentumL.), and red beets (Beta vulgarisL.). The lime treatments, check, calcitic lime, and dolomitic lime, were applied in 1979 and resulted in soil pH levels of 5.5, 6.9 and 6.7, respectively, at the time of planting. Banded fertilizer treatments were randomized in each lime plot. These were: check, NP, N, NPK, NPCa, and NPMg for snapbeans while with tomatoes and beets, K was added to the N, NPCa and NPMg treatments. Leaf samples from each plot were analyzed for 11 elements.

ISSN:0010-3624    

DOI:10.1080/00103628609367717

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103628609367710

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor