EFFECTS OF SURFACE SOIL PH ON SOIL CATION CONTENT, LEAF NUTRIENT LEVELS AND QUALITY OF APPLES IN BRITISH COLUMBIA

1982 ◽  
Vol 62 (3) ◽  
pp. 695-702 ◽  
Author(s):  
G. H. NEILSEN ◽  
P. B. HOYT ◽  
O. L. LAU

’Starkrimson’ Delicious (Malus domestica Borkh.), 10–15 yr old, on seedling rootstock, were sampled in several orchards, selected for uniformly low soil pH (< 5.0), medium pH and high pH (6.5–7.3). Harrold Red Delicious, 20–25 yr old, were sampled in 18 orchards which had low, medium and high pH within each. Soils with low pH were generally characterized by higher exchangeable Mn and lower exchangeable Ca. Exchangeable soil Mg and K levels were not significantly related to soil pH. On soils of low pH, higher leaf Mn was the main plant nutrient response with both Harrold Red and Starkrimson trees. Significantly decreased leaf Ca was observed on the younger Starkrimson trees at low soil pH. Soil pH had no direct effect on fruit firmness, soluble solids, juice acidity, or flesh Ca, Mg and K contents. Poststorage fruit quality problems were primarily surface scald and were not related to differences in soil pH. Incidence of flesh browning was, however, related to low flesh Ca content.

Soil Research ◽  
1994 ◽  
Vol 32 (2) ◽  
pp. 212 ◽  
Author(s):  
CR Ahern ◽  
MMG Weinand ◽  
RF Isbell

Surface soil pH can influence biological activity, nutrition and various chemical processes in the soil. Low pH or acidity is causing major concern in southern Australia, prompting requests for details on the extent, severity and distribution of acidic soils in Queensland. By creating a soil pH database, using an appropriate base map, rainfall isohyets and GIS technology, a coloured pH map of surface soils was produced at a 1:5000000 scale for the entire State. As most samples were from virgin or little disturbed sites, the map generally reflects naturally occurring soil pH. Developed horticultural, agricultural and fertilized pastoral areas are likely to have lower pH than that mapped. About two thirds (63.1%) of Queensland's soils have acidic surfaces, 9.5% neutral and the remaining 26.9% are alkaline. The major proportion (74%) of the > 1200 mm rainfall zone is strongly acid, and the remainder is medium acid or acid. Much of the sugar growing areas occur in this zone. Surface soil pH generally decreases as rainfall increases and to a lesser extent from subtropical to tropical climate. In addition to climate, identification of the soil type assists with predicting pH, as the organic, coarse and medium textured soils and massive earths are more likely to be acid and have low buffering capacity. Depending on the land use, such soils may require regular liming or minimizing of net acidifying practices for long term sustainability.


2020 ◽  
Vol 17 (6) ◽  
pp. 1451-1462 ◽  
Author(s):  
Jun Zhao ◽  
Yuanfeng Cai ◽  
Zhongjun Jia

Abstract. Soil pH is considered one of the main determinants of the assembly of globally distributed microorganisms that catalyze the biogeochemical cycles of carbon (C) and nitrogen (N). However, direct evidence for niche specialization of microorganisms in association with soil pH is still lacking. Using methane-oxidizing bacteria (methanotrophs) as a model system of C cycling, we show that pH is potentially the key driving force selecting for canonical γ (type I) and α (type II) methanotrophs in rice paddy soils. DNA-based stable isotope probing (DNA-SIP) was combined with high-throughput sequencing to reveal the taxonomic identities of active methanotrophs in physiochemically contrasting soils from six different paddy fields across China. Following microcosm incubation amended with 13CH4, methane was primarily consumed by Methylocystis-affiliated type II methanotrophs in soils with a relatively low pH (5.44–6.10), whereas Methylobacter- or Methylosarcina-affiliated type I methanotrophs dominated methane consumption in soils with a high pH (7.02–8.02). Consumption of 13CH4 contributed 0.203 % to 1.25 % of soil organic C, but no significant difference was observed between high-pH and low-pH soils. The fertilization of ammonium nitrate resulted in no significant changes in the compositions of 13C-labeled methanotrophs in the soils, although significant inhibition of methane oxidation activity was consistently observed in low-pH soils. Mantel analysis further validated that soil pH, rather than other parameters tested, had significant correlation to the variation in active methanotrophic compositions across different rice paddy soils. These results suggest that soil pH might have played a pivotal role in mediating the niche differentiation of ecologically important aerobic methanotrophs in terrestrial ecosystems and imply the importance of such niche specialization in regulating methane emissions in paddy fields following increasingly intensified input of anthropogenic N fertilizers.


1975 ◽  
Vol 85 (3) ◽  
pp. 395-401 ◽  
Author(s):  
O. A. Denton ◽  
W. J. Whittington

SUMMARYFour swede varieties and their six F1 hybrids were grown for 2 years in plots varying in pH from 4·2 to 8·4. Yields were highest at intermediate pH's and the average yield of the hybrids was greater than that of the parents. The plants on the low pH plots (4·2, 4·6, 4·7) were less infected with mildew than those at high pH (6·7, 7·7, 8·4). There was no marked resistance to mildew amongst the varieties. The response by the parents and hybrids was assessed by regression analysis and showed that the variety Reform was most reactive and Harvester most stable. Stability patterns appeared to be inherited. Inheritance patterns for yield and number of leaves were determined. It was concluded that selection for better swedes should be carried out in environments other than those to which the crop is currently restricted.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1025E-1026
Author(s):  
Wol-Soo Kim ◽  
Jung-An Jo ◽  
Soon-Ju Chung ◽  
Kil-Yong Kim ◽  
Hyun Sug Choi

The shells of crab, shrimp, beetles, etc., could be decomposed by chitinase to chitin, calcium, and protein, respectively. We incubated the mixture solution of 1.5 kg crab shell, 1.5 kg multinutrient, 2 kg compost with microorganisms to decompose the chitin substance, 3 kg sugar, and 700 L water at room temperature for 7 days. During the incubation, aeration with an air pump was essential. We sprayed the chitin-incubated solution (CIS) after filtering to `Niitaka' pear (Pyrus pyrifolia) trees at 15-day intervals from May to Sept. 2004. Leaf area, leaf thickness, leaf specific weight, and chlorophyll contents were increased by the treatment with CIS. In fruit characteristics, fruit weight, soluble solids, fruit firmness, and Hunter values “a” and “b”were increased by the CIS treatment. Flesh browning after peeling the fruit was delayed by the CIS treatment, and polyphenoloxidase (PPO) activities were lowered.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1084A-1084
Author(s):  
Wol-Soo Kim ◽  
Jung-An Jo

Many trials to supply germanium to fruit have been carried out since tests have confirmed germanium's role as a medical substance. Supplying germanium in orchards by soil and foliar application was not effective because of loss from rainfall. In order to increase germanium absorption by fruit, this study carried out tree trunk injections during the growing season. Two types of germanium, GeO (inorganic type) and Ge-132 (organic type), in concentrations of 5, 10, 25, and 50 mg·L–1 were supplied to `Niitaka' pear trees by trunk injection (1.5 L/tree), four times at 15-day intervals from June 2004. The treatment with 50 mg·L–1 GeO showed decreased fruit weight, but 50 mg·L–1 Ge-132 showed no difference to the control and other treatments. Fruit lenticels were increased in size by all of the Ge treatments in comparison to control fruit. Soluble solids as well as Hunter value `a' of the fruits of all Ge treatments were higher than that of the control. Flesh browning after peeling the fruit was delayed by the germanium treatment, and polyphenoloxidase (PPO) activities were lowered. Postharvest potentials were maintained at high levels for fruit firmness, physiological disorders, and decayed fruit during cold storage at 0 to 1 °C for 2 months.


1990 ◽  
Vol 30 (5) ◽  
pp. 637 ◽  
Author(s):  
PJ Dolling ◽  
WM Porter ◽  
AD Robson

Thirty-eight sites on acid soils (pH<5.5, 1:5 in water) in the medium rainfall region of Western Australia were sampled to examine spatial variation in soil pH and 0.01 mol/L CaCl2-extractable aluminium. We also examined the relationship between (i) the A1 and A2 horizon soil pH, (ii) the A1 and A2 horizon extractable aluminium, (iii) surface and subsurface soil pH and (iv) surface soil and subsurface soil-extractable Al. Soil at each site generally had a light-textured layer overlying a clay layer at varying depths (30-70 cm) and was classified as either Dy 5.21 or Dy 5.41 (Northcote 1979). Over 80% of the sites had surface soil pH values 4.8 or lower and extractable aluminium concentrations 2 �g/g or higher. There was a very poor correlation (r2 = 0.21) between the A1 horizon soil aluminium extracted in 0.01 mol/L CaCl2 and the pH measured in 0.01 mol/L CaCl2 over 1 ha sites. The relationship was slightly improved in the A2 horizon (r2 = 0.49). The coefficients of variation of soil pH varied from 1.2 to 5.1%, while the coefficients of variation for CaCl2-extractable aluminium varied from 10 to 50%. At many of the sites, low pH values and high aluminium concentrations extended down to 35-45 cm. At the B horizon the pH values generally increased and the aluminium concentrations decreased. The surface soil pH and extractable aluminium were not good indicators (r2 = 0.09-0.60) of the subsurface soil pH and extractable aluminium.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 995 ◽  
Author(s):  
CJ Smith ◽  
MB Peoples ◽  
G Keerthisinghe ◽  
TR James ◽  
DL Garden ◽  
...  

Changes in the chemistry of an acidic grey massive earth soil in response to various ameliorant treatments (gypsum and phosphogypsum in the presence or absence of lime) were investigated in a subterranean clover-based pasture in the southern highlands of New South Wales. Lime, gypsum, and phosphogypsum, or lime in combination with gypsum and phosphogypsum were broadcast at 2500 kg ha-1 on the surface of the soil in May 1990. Pasture production was determined and the soil was sampled to 25 cm depth, 6 and 18 months after treatment application. Surface soil pH was increased to 6-1 by the application of lime, gypsum plus lime and phosphogypsum plus lime treatments in the 0-5 cm depth interval, but remained unchanged when gypsum or phosphogypsum was used alone. Calcium chloride extractable aluminium increased down the soil profile under all treatments to 10-15 cm, but was highest in the gypsum treatment at depth. The application of phosphogypsum increased the 0.01 m CaCl2 extractable fluoride in the surface 5 cm from 26 to 43 �M. In contrast, fluoride concentrations were decreased to between 5.3 and 7.3 �M in the lime, gypsum plus lime and phosphogypsum plus lime treatments. Gypsum and phosphogypsum decreased the concentration of Al3+ in solution and on the exchange sites in the 0-5 cm depth interval. However, the effectiveness of the amendments to reduce toxic Al3+ concentrations were confined to the surface 5 cm. The concentration of aluminium and the activity of Al3+ in the 0-5 cm soil layer at both soil samplings were decreased by the amendments. Lime, and gypsum or phosphogypsum in combination with lime, were the most effective treatments for reducing the activity of Al3+. The activity of Al3+ increased with depth in all treatments. The pH and activity of Al3+ measured in the 0.01 m CaCl2 extracts plot near the gibbsite solubility line and suggest that Al solubility was controlled by this mineral. Exchangeable Ca in the 0-5 cm soil layer was significantly increased by the application of lime whereas exchangeable aluminium was decreased by lime, gypsum and phosphogypsum. There was no significant change in exchangeable cations other than Al below the surface 5 cm which suggests limited leaching of lime, gypsum and phosphogypsum in the profile within the 18 month study period. Pasture yield was significantly increased by the addition of lime and was related to the decrease in the activity of Al3+ in the surface soil.


2001 ◽  
Vol 33 (1) ◽  
pp. 75-82 ◽  
Author(s):  
K. I. Paul ◽  
A. S. Black ◽  
M. K. Conyers

2016 ◽  
Author(s):  
Xueru Huang ◽  
Xia Zhu-Barker ◽  
William R. Horwath ◽  
Sarwee J. Faeflen ◽  
Hongyan Luo ◽  
...  

Abstract. Iron (Fe) affects soil nitrogen (N) cycling processes both in anoxic and oxic environments. The role of Fe on soil N transformations such as mineralization, immobilization, and nitrification depends on its redox activity, which can be regulated by soil pH. We hypothesized that the effect of Fe oxide on N transformation processes would be different in soils as a function of pH. This study aimed to investigate N mineralization-immobilization, especially nitrification, as affected by Fe oxide in soils with different pH. A set of lab incubations under 100 % water holding capacity were carried out to investigate the effect of Fe oxide on N transformation rates in two subtropical agricultural soils with a low pH (pH 5.1) and a high pH (pH 7.8). 15N-labelled ammonium and nitrate were used separately to determine N transformation rates combined with Fe oxide (ferrihydrite) addition. Iron oxide addition stimulated net nitrification in the low pH soil (pH 5.1), while the opposite occurred in the high pH soil (pH 7.8). An explanation for this could be at low pH, Fe oxide increased NH3-N availability by stimulating N mineralization and inhibiting N immobilization. These results suggested that Fe oxide plays an important role in N transformations in soil ecosystem, and the effect of Fe oxide on N transformations depends on soil pH.


1967 ◽  
Vol 47 (3) ◽  
pp. 203-210 ◽  
Author(s):  
L. B. MacLeod ◽  
L. P. Jackson

The concentration of water-soluble and exchangeable aluminum was determined in the 0–15-, 15–23-, 23–30- and 30–45-cm depths of a Podzol limed to provide surface soil pH values ranging from 4.5 to 7.2. Both soluble and exchangeable Al decreased with increasing soil pH. Soluble Al ranged from 5.7 ppm at pH 4.4 with high fertilization to 0.3 ppm at pH 6.5 with similar fertilization. Increasing the rate of fertilization at pH 4.5 raised the soluble Al from 2.6 to 5.7 ppm. Fertilization still doubled the soluble Al in soil at pH 5.1 but had little effect as the pH was raised further to 5.8 and 6.5. Soluble Al in the subsoil samples was less than in surface soil samples at the same pH, while with exchangeable Al, the concentration was greater in the subsoil than in the surface soil samples.There was not a direct relationship between pH and soluble Al, although the highest soluble Al concentrations occurred at lowest soil pH levels. Analyses of 30 representative samples of surface soil taken from farmers' fields showed that the soluble Al concentration at pH 4.0 ranged from 3.5 to 4.8 ppm, while at a pH of 5.0 it ranged from 0.2 to 2.8 ppm. The concentrations of soluble Al in many of these soils exceeded the levels previously shown by nutrient solution experiments to severely restrict growth of legumes and some varieties of barley.


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