SOIL pH VARIATION IN BRITISH COLUMBIA APPLE ORCHARDS

1982 ◽  
Vol 62 (4) ◽  
pp. 695-698 ◽  
Author(s):  
G. H. NEILSEN ◽  
P. B. HOYT

Soil pH variation was examined in British Columbia apple orchards. Soil pH tended to increase as distance from the tree trunk and depth from the soil surface increased. However, pH variation from tree to tree was frequently significant both for widely separated trees in orchards where pH was expected to be variable and for adjacent trees in orchards expected to have uniform soil pH. To represent orchard blocks adequately, emphasis should, therefore, be placed upon collecting samples from many rather than a few trees. Nonetheless, the possibility of decreased soil pH near trees can not be ignored in sampling individual trees.

1977 ◽  
Vol 57 (2) ◽  
pp. 157-164 ◽  
Author(s):  
D. C. PENNEY ◽  
M. NYBORG ◽  
P. B. HOYT ◽  
W. A. RICE ◽  
B. SIEMENS ◽  
...  

The amount of cultivated acid soil in Alberta and northeastern British Columbia was estimated from pH values of farm samples analyzed by the Alberta Soil Testing Laboratory, and the effect of soil acidity on crops was assessed from field experiments on 28 typical acid soils. The field experiments consisted of two cultivars of barley (Hordeum vulgare L.) and one cultivar each of rapeseed (Brassica campestris L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) grown with and without lime for 2 yr. There are about 30,000 ha of soils with a pH of 5.0 or less where soil acidity seriously restricts yields of all four crop species. There are approximately 300,000 ha with a soil pH of 5.1–5.5 where liming will on the average increase yields of alfalfa by 100%, yields of barley by 10–15%, and yields of rapeseed and red clover by 5–10%. There are a further 1,600,000 ha where soil pH ranges from 5.6 to 6.0 and liming will increase yields of alfalfa by approximately 50% and yields of barley, rapeseed and red clover by at least 4–5%.


1977 ◽  
Vol 57 (1) ◽  
pp. 297-299 ◽  
Author(s):  
A. G. FISHER ◽  
G. W. EATON ◽  
S. W. PORRITT

A study in Delicious apple orchards in the Okanagan Valley showed that severe symptoms of internal bark necrosis were generally associated with soil pH below 5.6 and leaf manganese above 120 ppm. Some exceptions, however, show that both these determinations are required for accurate diagnosis of tree symptoms.


2017 ◽  
Vol 36 (01) ◽  
pp. 70-76 ◽  
Author(s):  
Humair Ahmed ◽  
Muhammad Tariq Siddique ◽  
Muhammad Iqbal ◽  
Fayyaz Hussain

2014 ◽  
Vol 147 (2) ◽  
pp. 227-243 ◽  
Author(s):  
V. Marius Aurelian ◽  
Maya L. Evenden ◽  
Gary J.R. Judd

AbstractApple clearwing moth (ACM),Synanthedon myopaeformis(Borkhausen) (Lepidoptera: Sesiidae), is an invasive species and destructive pest of commercial apple trees in British Columbia (BC), Canada. Mass trapping with Concord grape juice and sex pheromone is being developed as an organic pest management tactic. We quantified the diversity and abundance of arthropod by-catch in these traps during the 2009 flight (13 June–31 July) of ACM. Paired traps were deployed in organic and conventionally managed apple orchards planted using different tree densities representing the extremes of the current BC apple industry. Using seasonal by-catch and community-level statistical analyses we determined that family communities of arthropods caught in juice-baited and pheromone-baited traps differed significantly. Yellow juice-baited traps caught a greater variety of arthropod families in greater abundance than pheromone-baited yellow Unitraps®. We show that for each trap type, family communities caught in organic versus conventional orchards were significantly different. Organic orchard management affected abundance of some beneficial taxa, but the sign of the difference depended on the taxon examined (e.g., ladybeetles increased versus lacewings declined). Tree density had no effect on by-catch. Managing ACM by mass trapping may be detrimental to ecosystem services because many nontarget beneficial species are caught. A balanced risk-to-benefit approach should be taken before this technology is widely implemented against ACM.


1957 ◽  
Vol 37 (2) ◽  
pp. 108-112
Author(s):  
F. L. Banham ◽  
R. H. Handford

Emulsions of dieldrin, aldrin, isodrin, toxaphene and chlordane applied to the soil surface and incorporated to a depth of about 4 inches proved highly effective in controlling the red-back cutworm, Euxoa ochrogaster (Guen.) when tested in asparagus fields in the interior of British Columbia in the summer of 1953 and 1954. In 1953 aldrin emulsion mixed with the soil was much more effective than when it was left on the soil surface, Bran bait containing paris green, although giving fairly satisfactory control, was less effective and slower in action than the emulsions. In 1952, dieldrin, aldrin, and isodrin dusts, applied to the soil surface, were superior to and faster in action than bran baits containing aldrin or endrin; all of the 1952 treatments were apparently slower in action in dry soil than in relatively moist soil. A survey of asparagus fields treated by growers in 1953 but not in 1954 indicated that aldrin emulsion, mixed with the soil at about 4 lb. of toxicant per acre, protects asparagus for at least two years.


Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 719-722 ◽  
Author(s):  
J. J. Kells ◽  
R. L. Blevins ◽  
C. E. Rieck ◽  
W. M. Muir

Field studies were conducted to determine the effect of soil surface (upper 5 cm) pH and tillage on weed control and corn (Zea maysL.) yield using simazine [2-chloro-4,6-bis-(ethylamino)-s-triazine] as the herbicide for weed control. Soil pH, weed control, and corn yield were examined under no-tillage and conventional tillage systems with and without added lime and different rates of nitrogen. Increased soil pH significantly increased weed control as compared with added lime vs. no added lime, where the surface soil pH influenced the effectiveness of the applied simazine. Soil pH had a greater effect on weed control under no-tillage than under conventional tillage. Conventional tillage significantly (P<.01) increased weed control, yield, and soil pH over no-tillage. Additions of lime as compared to unlimed treatments resulted in significantly increased weed control (83% vs. 63%), yield (5,930 vs. 5,290 kg/ha) and soil pH (5.91 vs. 5.22). The poorest weed control was observed with no-tillage on unlimed plots. A significant tillage by linear effect of nitrogen interaction for all variables resulted from a greater decrease (P<.01) in weed control and soil pH and a greater increase in yield with increased nitrogen under no-tillage than with conventional tillage.


2009 ◽  
Vol 85 (3) ◽  
pp. 387-391
Author(s):  
Mihai Pavel ◽  
Björn O Andersson

A model for predicting the value of forest stands was developed at FPInnovations – Feric Division. The model uses standard cruise data collected in British Columbia (BC) and company sort descriptions to predict the distribution of wood volume by species and grade sort for each proposed harvest site. The model is capable of quickly analyzing different scenarios (i.e., different sort sets) to reflect changing market conditions. Within the model, a taper equation is applied to each tree to calculate the diameters inside the bark, and quality and pathological descriptors from cruise data are used. A Dynamic Programming algorithm is used to predict the combination of logs that maximizes the value of each stem, and results are summarized and extended from individual trees to cruise plots, then to harvest blocks and/or stands. The model was successfully tested for second-growth stands with relatively few defects on Coastal BC. Improvements are being implemented to enhance its applicability to more complex stands. Key words: value of forest stands, economic operability, optimal bucking of trees, Dynamic Programming, computer model, inventory systems


1983 ◽  
Vol 63 (2) ◽  
pp. 401-403
Author(s):  
C. B. CHAMPTON

Colorimetric soil pH measurements made systematically across Burnaby Mountain in well-drained loamy soils of the rainforest of British Columbia over an 8-yr period from 1974 until 1981 showed that acidification of the subsoil increased after two consecutive drier-than-average years. This changing acidity contrasted with the relatively stable acidity of the subsoil in imperfectly drained soils, regardless of changing patterns of precipitation. Key words: pH, forests, loams, precipitation


1977 ◽  
Vol 57 (3) ◽  
pp. 361-370 ◽  
Author(s):  
M. D. WEBBER ◽  
DIANE CORNEAU ◽  
P. B. HOYT ◽  
M. NYBORG

Several laboratory methods for estimating lime requirements of acid soils were compared using 24 soils from Alberta and northeastern British Columbia and 15 from elsewhere in Canada. The Peech, Schofield, Woodruff and SMP (Shoemaker et al. 1971) buffer methods were equally well correlated with lime requirements for raising soil pH to 5.5 or 6, which in turn were highly correlated with the amounts of soluble and exchangeable Al and organic matter in the soils. The SMP buffer method is recommended for use as the diagnostic index of lime requirement to achieve pH 5.5 or 6 because of its speed and simplicity. A refinement is suggested for Alberta and northeastern B.C. soils on the basis that lime need not be added to achieve pH 5.5 but should be added to reduce Al below the toxic level for sensitive crops. The lime requirements to reduce Al in those soils were highly correlated with the amounts of 0.02 M CaCl2-soluble Al they contained and it is recommended that the 0.02 M CaCl2-soluble AI be used as the diagnostic index of lime requirement. Lime requirements related to SMP (pH) and 0.02 M CaCl2-soluble Al are presented.


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