Comparison of methods for determining lime ...

New Zealand Journal of Agricultural Research

ISSN: 0028-8233 (Print) 1175-8775 (Online) Journal homepage: http://www.tandfonline.com/loi/tnza20

Comparison of methods for determining lime requirements of New Zealand soils D. C. Edmeades , D. M. Wheeler & J. E. Waller To cite this article: D. C. Edmeades , D. M. Wheeler & J. E. Waller (1985) Comparison of methods for determining lime requirements of New Zealand soils, New Zealand Journal of Agricultural Research, 28:1, 93-100, DOI: 10.1080/00288233.1985.10427001 To link to this article: http://dx.doi.org/10.1080/00288233.1985.10427001

Published online: 24 Jan 2012.

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Date: 28 January 2016, At: 11:01

New Zealand Journal of Agricultural Research, 1985, Vol. 28: 93-100 0028-8233/85/2801-0093$2.50/0 © Crown copyright 1985

93

Comparison of methods for determining lime requirements of New Zealand soils

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D. C. EDMEADES D. M. WHEELER J. E. WALLER Ruakura Soil and Plant Research Station, MAF Private Bag, Hamilton, New Zealand

Abstract Methods for measuring the lime requirement (LR) of New Zealand mineral soils were evaluated. All the laboratory methods examined underestimated the LR to reach a target pH of 6.0 as determined from field trials (field LR). The Shoemaker, McLean, and Pratt (SMP) single and double buffer methods, the Adams-Evans buffer method, and a Ca(OHh titration procedure gave similar correlations with field LR (rank correlation coefficients (r,) = 0.68, 0.77, and 0.67 respectively). Yuan's buffer method and Metson's base saturation method were poorly correlated with field LR (r, = 0.52 and 0.34 respectively). Field LR was significantly correlated with soil pH (H 20) and exchangeable aluminium (r, = 0.66 and 0.66), and was not related to soil texture. Regression analysis showed that a simple model based on soil pH plus organic carbon (%C) or cation exchange capacity (CEC) could account for 43% of the variation in field LR. This model was successfully used to predict the field LRs of a further 24 soils. Keywords soil testing

lime; lime requirements; fertilisers;

Russell (J 973) discussed some of the problems involved in measuring soil LRs, and reported that laboratory methods underestimate LRs determined in field trials. Despite this most studies use either a laboratory titration procedure or a laboratory incubation procedure as standards against which other laboratory LR tests are calibrated (Keeney & Corey 1963; Webber et al. 1977; McLean et al. 1977). In this paper we report an evaluation of 6 methods for measuring LR. The methods were evaluated against field LR - the amount of lime required to achieve a soil pH of 6.0 determined from field trials. Models for predicting field LR are also examined.

MATERIALS AND METHODS Soils The soils used in this investigation were collected from 2 series of existing lime trials on permanent pasture. Both series used a randomised block design, with 6 replicates of 5 treatments (0, l.25, 2.5, 5.0, and 10.0 tjha limestone) or 8 replicates of 4 treatments (0, l.25, 2.5, and 5.0 t/ha limestone). A composite sample (0-75 mm) from the control plots (unlimed) of each trial was collected either during or at the conclusion of the trial and air-dried and sieved (2 mm). The samples represent a range of soil groups and properties (Table 1).

LR methods INTRODUCTION To determine the amount of lime (ground limestone) required on a given soil to achieve maximum production it is necessary to know: (1) the optimum soil pH for the crop being grown; and (2) the amount of lime required to achieve the optimum pH - the lime requirement (LR). There is much field evidence in New Zealand which shows that the optimum pH for grassland soils is 5.8-6.0 (Edmeades et al. 1984). In contrast there is v~ry little information on the LRs of New Zealand SOlIs.

Received 12 December 1983; revision 9 August 1984

Field Field lime requirement (field LR) was determined from field trial data from each trial by determining the regression equation between soil pH (y) and the rate of lime applied (x). Generally soil pH determinations were made from each plot biennially for 4-5 years following liming. The first year's data were omitted because at least 1 year is required for lime to reach its maximum effect on soil pH. Also there was no evidence from the trials that soil pH declined within the first 5 years following liming. The pH was averaged over all years for each plot, giving 30 or 32 data points for each regression. The regression equation used, adjusted for blocks, was y = ax + b.J x + c

6.0 5.2 5.2 5.9 5.7 5.5 5.8 5.8 5.6 5.9 5.4 5.9 5.3 5.8 5.6 5.4

Recent Rotomahana silt loam Hokitika fine sandy loam Hokitika sandy loam

Yellow-brown loam Pihama sandy loam Rowan coarse sandy loam Inglewood coarse sandy loam Norfork sandy loam New Plymouth brown loam Patua sandy loam Hangatahua sandy loam Mairoa sandy loam Kahui sandy loam Te Kowhai sandy silt loam

Yellow-brown pumice soil Kaharoa sand Taupo sandy silt Mamaku sandy loam

not determined.

5.5 6.0 5.8

Yellow-grey earth Kokotau silt loam (A) (B) Timaru silt loam

=

5.2 5.6 5.1 5.3

Yellow-brown earth Omanaia clay Autea clay Waipori silt loam Kaiwera silt loam

ND

Water

pH

Soil group and type

Table 1 Soils and properties.

4.8 4.8 4.5

4.9 4.6 4.7 4.7 5.0 4.6 4.7 4.8 4.8 4.5

5.2 4.0 3.9

4.3 4.9 5.0

4.2 4.7 3.8 4.2

KCI

14.7 35.1 29.0

45.7 29.3 38.5 36.3 51.0 41.7 33.4 59.3 36.4 27.9

18.5 19.7 13.9

17.1 20.0 15.5

32.6 30.5 24.4 26.0

CEC at pH 7 (me./100 g)

42.2 45.8 17.8

24.5 19.4 20.3 14.3 33.6 12.1 31.4 19.3 24.0 39.3

77.3 24.2 43.5

60.4 62.8 67.0

55.7 73.0 24.3 30.8

(%)

Base saturation

12.1 12.2 10.0

15.2 13.0 16.3 17.9 15.5 19.3 14.9 18.5 12.7 6.1

4.2 6.6 4.6

4.6 4.1 3.8

8.8 7.2 5.2 6.4

(%)

0.42 0.88 0.64

1.00 0.73 0.90 0.25 0.16 0.74 0.83 1.08 0.86 0.52

0.31 0.43 0.29

0.32 0.29 0.28

0.56 0.45 0.32 0.41

(%)

Carbon Nitrogen

820 590 730

670 680 700 630 720 660 700 610 700 920

950 770 850

860 870 940

830 880 890 870

w/v (kg/m3)

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4 3 2

4 0 4 ND 7 12 7 6 11 35

13 13 3

15 20 35

36 38 25 37

(%)

Clay

7 31 21

37 21 22 ND 34 24 34 28 24 23

30 42 28

40 41 23

47 29 24 27

(%)

Silt

24 55 57

53 35 43 ND 45 43 45 50 52 38

41 39 58

44 39 38

16 31 43 34

(%)

65 12 20

6 45 31 ND 14 21 14 15 13 4

16 6 11

1 2 7 2

(%)

Fine Coarse sand sand

0.15 0.09 0.02

0.13 0.15 0.1 0.15

0.18 0.11 0.93

0.05 0.03 0.16 0.11 0.02 0.89 0.08 0.32 0.33 0.31

0.16 0.05 0.08

0.02 0.05 0.08 0.14 0.11 0.05 0.45 0.12 0.48 0.38