Wood Ash and Fertilizer Effects on Crop Production and Soil Properties for an Acidic Soil Wood ash has been observed to be an excellent substitute to lime, mostly better. A project was started in 2006 to study the effects of wood ash and recommended fertilizers applications for an acidic soil near Falher (NW16-77-21-W5) on a Gray Wooded soil with a pH of near 6. The treatments were Check (no fertilizer or wood ash), Fertilizers (Fert) - soil test based fertilizers, Wood Ash (Ash) - wood ash rate to supply equivalent amounts of phosphorus in the fertilizer treatments, and Wood Ash + Nitrogen Fertilizer (Ash+N) - Same as # 3 + soil test based nitrogen (N) fertilizer. For peas, the fertilizer N was replaced with inoculums. Three sets of the treatment plots were laid out at the North, Centre and South locations. Recommended rates of fertilizers and wood ash (3000 lb/ac in 2006 and 3911 lb/ac in 2007) were used in designated treatments in 2006 and 2007. Wood ash was spread on the soil surface. All plots were rotortilled. The phosphate fertilizer was seed placed. Canola (north), Peas (centre), and barley (south) were grown in 2006. Oats were grown in all plots in 2007. In 2008 and 2010, wheat was grown in all the plots using only blanket rates of 46-0-0 in all plots. Soil samples cores were collected from the 0-6 inch soil in May 2007 and October 2008. Wood ash had a bulk density of 624 g/L (50.6 lb/bu) and had 900 mL water/ L at saturation. It showed presence of all the essential plant nutrients. Amounts of other elements were low and did not appear to pose a problem. Considering the concentration of various nutrients, application of wood ash to meet the phosphorus (P) requirement of a crop may be able to supply adequate amounts of essential plant nutrients, except N. Peas yield in 2006 was Ash+N > Fert ≅ Ash > Check. Maximum 2006 barley and 2007 oats seed yield were from the Ash+N treatment, followed by Fert, Ash and Check in decreasing order. In 2008 and 2010, the wheat yield was greater from the Ash and Ash+N treatments compared to both the Check and Fert treatments, and showed no effect of the fertilizer applications. Compared to the Check and Fert treatments, the treatments with wood ash had or tended to have higher pH, potassium, calcium, phosphorus, sulphur, zinc, manganese, iron, copper, chloride and sodium levels in soil. Unlike the wood ash, applications of fertilizers tended to reduce the pH and calcium levels in soil. (Full report on PP ??)

Wood Ash and Fertilizer Effects on Crop Production and Soil Properties for an Acidic Soil Background The estimated area of acidic (low pH) soils is 14.9 million acres in the Western Canada and 1.35 million acres in the Peace Region (Agdex 534-2, 2002). Research has shown wood ash to be an excellent substitute to lime, mostly better, apparently due to the presence of other plant nutrients in wood ash compared to only calcium and magnesium in agriculture lime (Agdex 534-2, 2002). Residual effects of both lime and wood ash have been observed for a number of years. Wood ash samples from Tolko Industires Ltd. in High Prairie contained all the nutrients essential for plants in variable amounts, except nitrogen (N). Thus it can be a good source of several essential plant nutrients. A project was started in 2006 to study the effects of wood ash and recommended fertilizers applications for an acidic soil near Falher. The results for the 2006, 2007 and 2008 have been reported in the Annual Reports of SARDA (2006, 2007 and 2008). The objective of this report is to update the results until 2010.

1

Methods Wood ash was collected from the Tolko Industries, High Prairie, in May 2006. Some physical properties of wood ash were determined and a sample was sent for chemical analyses. The treatments in 2006 were as follows. 1. Check: No fertilizer or wood ash. 2. Inorganic Fertilizers (Fert): Soil test based fertilizer rates; or Fert + Inoculums (Fert+In): For peas. 3. Wood Ash (Ash): The amount of wood ash application was based on approximate available phosphorus (1% P2O5) in it, to supply equivalent amounts of phosphorus as in the fertilizer treatment. 4. Wood Ash + Nitrogen Fertilizer (Ash+N): Same as # 3 + soil test based nitrogen (N) fertilizer; or Ash + Inoculums (Ash+In): For field peas. The experimental site (NW16-77-21-W5) has a Gray Wooded soil with a pH of near 6. Three sets of the treatment plots were laid out at the North (canola), Centre (field peas) and South (barley) locations. Randomized Complete Block Design (RCBD) with four replications was used to layout test plots with 6 crop rows (7 m long x 1.2 m wide in 2006; 8 m long x 1.4 m wide in later years). In 2006, wood ash (3000 lb/ac in the Ash and Ash+N treatment plots), nitrogen fertilizer (74 lb N/ac in the Ash+N and Fert treatments for canola and barley) and sulphur fertilizer (22 lb S/ac in the Fert treatment for canola) were spread on the soil surface of the designated plots. Before seeding, all the plots were rotor-tilled. In all the Fert treatment plots, phosphate fertilizer (30 lb P2O5/ac) was seed placed. Canola (North), peas (Centre) and barley (South) were grown using recommended agronomic practices. In 2007, soil samples were collected in May to compare the effects of 2006 treatments on soil properties in the 0-6 inch depth. Wood ash (3911 lb/ac) was spread on the soil surface of the Ash and Ash+N treatment plots. It was followed by rotor-tillage in all plots. The nitrogen (70 lb N/ac in the North and South Ash+N and Fert treatment plots) and sulphur fertilizer (10 lb S/ac in the North Fert treatment plots) were banded below the seed row. The phosphorus fertilizer (35 lb P2O5/ac in all the Fert treatment plots) was seed placed. Derby oats were grown using recommended agronomic practices. In 2008, wheat (Harvest) was grown in all the plots using recommended agronomic practices. Blanket rate of 46-0-0 (150 lb/ac) was banded in all plots at seeding. Soil samples cores were collected from the 06 inch soil on October 2, 2008 to compare the treatment effects. In 2009, peas (North), flax (Centre) and canola (South) were grown using recommended agronomic practices and applying same amount of fertilizer to the given crop in all treatments. However, no data were collected due to unevenness of crop growth. In 2010, Roundup Transorb was applied on May 14 for pre-seed burn off. Wheat (Harvest) was seeded in all the plots on May 14, using recommended agronomic practices. Blanket rate of 46-0-0 (130 lb/ac) was banded in all plots at seeding. Assert (0.67 L/ac) plus Curtail M (0.81 L/ac) were sprayed on June 8. Plant height was measured on Aug. 5 and head samples for maturity were collected on Aug. 17. Crop was harvested on Sept. 22. Data were subjected to analyses of variance (ANOVA) using ARM. The 2008 and 2010 data shows the residual effects of wood ash and fertilizer applications in 2006 and 2007. More details on the methods are available in 2006, 2007 and 2008 Annual Reports of SARDA.

Microbial soil properties measurements in 2009 Samples were collected from the crop rhizosphere soil and bulk soil at the flowering stage of canola in 2009. Plants were excavated from four 0.5-m row lengths, selected randomly, in each plot. Loose soil was removed from the roots and the soil strongly adhered to the roots was recovered as rhizosphere soil. Bulk soil (0-7.5 cm depth) was sampled from the middle of two adjacent crop rows of the four 0.5-m row lengths locations. The four bulk or rhizosphere samples from each plot were combined, passed through a 2-mm sieve and stored at 4 ºC until analysis. Soil microbial biomass C (MBC) was measured using the substrate-induced respiration (SIR) method, in which 300 mg of glucose was dissolved in 4.5-6.0 mL water and added to 50 g soil to bring it to 50% water-holding capacity. After stir-mixing, the soil was incubated in a 1L jar for 3 h at 22 ºC and the amount of CO2 that accumulated in the head space was measured by gas chromatography. Community level physiological profiles (CLPP) were evaluated using the Biolog® method, which tests the ability of a microbial community to utilize different C substrates contained in a micro plate (Eco-plate®). The procedure was adapted by colorimetrically standardizing inoculum densities in 1 g soil samples to about 103 cells mL-1. Aliquots of 150 µL of the soil suspension were added to Biolog Ecoplate® microplates containing 31 substrates and a water control. The plates were incubated at 28 ºC without shaking. Optical densities in the wells were read with an enzyme-linked immunosorbent assay (ELISA) plate reader at 590 nm after 48 h of incubation. The optical density readings were corrected for the water controls in subsequent analyses. Negative readings after the correction were adjusted to zero. On the basis of CLPPs of each treatment, Shannon index (H’) of functional diversity was calculated, as well as its components: substrate richness (S) and substrate evenness (E). The MBC, H’, S and E data were subjected to analysis of variance. Rhizosphere and bulk soil data were analyzed separately. Where treatment effects were significant, means were separated by the least significant difference (LSD) test at 95% level of significance. Principal Component Analysis (PCA) was used to classify treatments according to their CLPPs. A covariance matrix was used in PCA analysis. After classification of treatments with PCA, the substrates that accounted for differences between classes of treatments in substrate utilization were identified by correlating principal component scores with optical density readings for individual substrates. Results are presented graphically as bi-plots. Results Wood ash properties Wood ash had a bulk density of 624 g/L (50.6 lb/bu) and had 900 mL water/ L at saturation. As expected, wood ash sample showed presence of all the essential plant nutrients (Table 1). Amounts of other elements were low and did not appear to pose a problem (data not shown). An earlier study indicated that up to 7.5 t/ha (6690 lb/ac) could be used without exceeding the limits by the Alberta Environment. Considering the concentration of various nutrients, application of wood ash to meet the phosphorus (P) requirement of a crop may be able to supply adequate amounts of essential plant nutrients, except N. Table 1. Concentration of plant nutrients in

wood ash. Nutrient Phosphorus Potassium Sulphur Calcium Magnesium Iron Zinc

kg/t 7.88 69.00 6.58 324.00 18.40 6.90 2.86

Nutrient Barium Boron Cobalt Copper Manganese Molybdenum

g/t 1830 226 6 69 635 9

Crop production Application Years (2006 and 2007): In 2006, maximum barley seed yield was from the Ash+N treatment (Fig. 1, Table 1). Compared to Check, the yield increase was 50.1 bu/ac from Ash+N, 39.0 bu/ac from Fert, and 18.2 bu/ac from Ash treatment. Thus Ash+N had 11.1 bu/ac more barley yield than the Fert treatment. Like barley, maximum peas yield in 2006 was with the Ash+N (Fig. 1, Table 1). Compared to Check, the yield increase was 18.8 bu/ac from Ash+N, 14.2 bu/ac from Fert, and 13.4 bu/ac from Ash. Thus Ash+In had 4.6 bu/ac peas yield advantage over the Fert+In treatment. The Ash treatment produced similar yield as the Fert+In. The 2007 oats seed yield increase at the South location was 45.5 bu/ac by Ash+N, 31.0 by/ac by Fert and 9.9 by/ac by Ash (Fig. 2, Table 1). Thus the Ash+N produced 14.5 bu/ac extra oats than the Fert treatment. No data could be collected from the Fert and Ash+N treatments in the North and Centre locations, due to adverse effect of N fertilizer (Fert and Ash+N) on emergence of crops. 150 100

Fig. 1. 2006 Center (peas ) and South (barley) yield (bu/ac) Check

Fert

Ash

Ash+N

50 0 Centre 150 125 100

South

Fig. 2. 2007 Oats yield (bu/ac) Check

Fert

Ash

Ash+N

75 50 25 0 North

Centre

South

Residual Effects (2008 and 2010): In 2008, the Ash and Ash+N treatments tended to produce more wheat yield compared to both the Check and Fert treatments, though the differences were not always

significant (Fig. 3, Table 1). Averaged across the 3 locations, both the Ash and Ash+N treatments produced 3.5 and 3.8 bu/ac more yield than the Check and Fert treatments, respectively. Unlike wood ash application, the 2008 wheat yield showed no effect of the fertilizer application in 2006 and 2007, as indicated by very similar yield from the Check and Fert treatments (Fig. 3, Table 1). Similarly, the Ash and Ash+N treatments produced equivalent wheat yield. The plant height, maturity and bushel weight of the 2010 wheat was not influenced by the treatments (data not shown). However, like 2008 the Ash and Ash+N treatments always produce more wheat yield (range of 2.0.4 to 7.2 bu/ac) than the Check and Fert treatments, though the differences were not always significant (Fig. 4, Table 1). Averaged across the 3 locations, the increase in wheat yield over the Check was 4.4 and 3.9 for the Ash+N and Ash treatments, respectively. The differences between the Check and Fert treatment were relatively small and inconsistent. 40 30

Fig. 3. 2008 Wheat yield (bu/ac) Check

Fert

Ash

Ash+N

20 10 0 North 50

Centre

South

Fig. 4. 2010 Wheat yield (bu/ac)

40

Check

Fert

Ash

Ash+N

30 20 10 0 North

Centre

South

Table 2. Effects of fertilizer and wood ash treatments, applied in 2006 and 2007, on the seed yield. Location Check Fert Ash Ash+N LSD95% CV% a 2006 Seed yield, kg/ha (bu/ac ) for different crops North (Canola) NDb ND ND ND ND ND Centre (Peas) 3977(59.2) 4923(73.4) 4870(72.6) 5237(78.0) 790.3(11.81)* South (Barley 3753 (69.8) 5849(108.8) 4730(88.0) 6447(119.9) 1017.3(18.94)** 12.2

North Centre South

2007 Oats Seed yield, kg/ha (bu/aca) 3121(81.8) ND 3102(81.3) 3132(82.0) ND 3394(88.9) 3461(90.7) 4646(121.7) 3842(100.6) 2008 Wheat Seed yield, kg/ha (bu/aca)

ND ND 5197(136.2)

474.5(12.46)NS 1188.3(31.2)NS 1136.7(29.77)*

3.6 12.0 14.6

North Centre South Mean

1549 (23.0) 1574 (23.4) 1748 (26.0) 1624 (24.1)

1617 (24.0) 1542 (22.9) 1643 (24.4) 1601 (23.8)

1799 (26.8) 1880 (28.0) 1889 (28.1) 1856 (27.6)

1773 (26.4) 1717 (25.5) 2072 (30.8) 1854 (27.6)

248 (3.69)NS 223 (3.33)* 258 (3.81)*

2010 Wheat Seed yield, kg/ha (bu/aca) North 2098(31.2) 2334(34.6) 2585(38.4) 2358(35.0) 332.3(4.92)NS Centre 1648(24.5) 1623(24.1) 1913(28.4) 1956(29.0) 197.8(2.92)† South 1643(24.4) 1712(25.4) 1822(27.0) 1854(27.5) 366.9(5.44)* Mean 1796(26.6) 1890(28.0) 2107(31.3) 2056(30.5) a Refers to yield in bu/ac. b ND refers to not determined. **, * and † refers to treatment effect being significant at 99%, 95% and 90%, respectively. significant at 90%.

9.2 8.3 8.7

8.8 6.9 13.0

NS

being not

Soil properties: Compared to the Check and Fert treatments, the treatments with wood ash had significantly higher pH, potassium, calcium and zinc levels, and tended to have higher (not significantly) phosphorus, sulphur, manganese, iron, copper, chloride and sodium levels (SARDA Annual Report, 2008). Similarly, the percentage of potassium, calcium and sodium relative to the cation exchange capacity (CEC) was greater in soil where wood ash had been applied. Also the wood ash application tended to increase phosphorus saturation of soil and potassium/magnesium ratio. Similar results were observed form the soil samples collected in May 2007 (SARDA Annual Report, 2007). Unlike the wood ash, application of fertilizers (Fert treatment) tended to reduce the pH and calcium levels in soil and increase the percentage of hydrogen relative to the cation exchange capacity (CEC) of soil in comparison to the Check plots. Soil acidification due to nitrogen fertilizer application has been known to occur. Recommendations of lime, phosphorus and potassium use for a canola crop in 2009 were lower in the wood ash receiving treatments (Ash and Ash+N) compared to the Check and Fert treatments (SARDA Annual Report, 2008). Compared to the 1 ton/ac for the Check and 4 ton/ac for the Fert treatment plots, no lime application was recommended for the plots receiving wood ash application in 2006 and 2007. These data showed a potential of saving on the input costs for the 2009 crop.

Microbial biomass and diversity in soil There were no significant differences between the treatments MBC, in either the rhizosphere or bulk soil of canola plots (Table 3). Similarly, none of the indices of microbial diversity (H’, S, E) were different between treatments in canola rhizosphere or bulk soil (Table 3). Multivariate analysis of substrate utilization patterns revealed treatment-related shifts in the CLPPs of bacterial communities. In canola rhizosphere soil, the composition of microbial communities in the fertilizer treatment was different from the other treatments (Fig. 5, where the fertilizer treatment is on the right-hand side while the rest of the treatments are on the left-hand side). The substrate vectors show that most substrates were utilized more in the fertilizer treatment than in the other treatments, i.e., most of the vectors are pointing towards the fertilizer treatment. In bulk soil, it was the check treatment which had different composition of microbial communities than the rest of the treatments (Fig. 6).

These results show that these treatments affected the composition of microbial communities even though the overall microbial biomass and diversity were not affected. Such subtle shifts in microbial communities can be very important because different microorganisms perform different functions in the soil. Discussion & Conclusions: Traditionally, calcitic limestone (CaCO3, commonly known as agriculture lime) has been used to reduce soil acidity in western Canada. Wood ash normally have about 30% calcium (Ca) compared to about 40% Ca in agriculture lime. Samples from some facilities have shown wood ash to have calcium carbonate equivalent (CCE) in the range of 55 to 100%. Earlier wood ash samples from Tolko have shown total neutralizing value ranging from 79 to 108% (average about 90%) and effective neutralizing value ranging from 41 to 96% (average about 71%). Thus the effectiveness of wood ash for reducing soil acidity based on the calcium percentage appears to be somewhat lesser than agriculture lime. However, wood ash contains materials similar to the oxide and hydroxide forms of lime and thus is likely to be more effective to reduce soil acidity than the CaCO3 material in agriculture lime. But considering the CCE value and potential for faster movement in to deeper soil may make wood ash to be equal or superior to agriculture lime to reduce soil acidity. Previous research has shown more rapid change in soil pH with wood ash relative to agriculture lime (Agdex 534-2). In most of the previous studies to compare reduction in soil acidity using agriculture lime and wood ash, similar amounts of chemical fertilizers have been applied to all the plots. In the present study, making use of essential plant nutrients present in wood ash was an attempt to reduce the costs and chemical fertilizer requirements. This could encourage more producers to consider wood ash to reduce soil acidity because saving on fertilizer costs would offset some of the costs to apply wood ash. Increase in seed yield crops from application of wood ash alone (Ash treatment) in the present study, without concurrent nitrogen application, showed its beneficial effects due to liming and essential nutrients. Also the Ash+N treatments tended to produce more seed yield compared to the Fert treatment. Thus, the crops may have benefited from the combined effects of other nutrients present in wood ash and change in soil pH, microbial biomass, and soil tilth. Regarding the residual effects, increase in the values of soil pH, some nutrients and other soil properties clearly indicated residual effect of wood ash application to improve these soil properties. Apparently, this improvement in soil quality was responsible for the increase in 2008 and 2010 wheat yield due to wood ash application in previous two years. Other studies have shown lime and wood ash to be effective in increasing crop yield for several years (Agdex 534-2). It is therefore suggested to consider the effects of wood ash during the year of application and in terms of residual effects in the following years. Considering the continued benefits of wood ash for crop production and soil properties in this study, further monitoring of residual effects will be continued. Acknowledgements Tolko Industries Ltd. – funding, wood-ash & consultation for the 2006 and 2007 trials.

Table 3. Microbial biomass properties in the rhizosphere and bulk soil from the canola plots in 2009. Bulk soil Rhizosphere soil Treat Micro Substrate Substrate BMicro Substrate Substrate BC Richness Evenness SahnnonI Gluco C Richness Evenness SahnnonI Gluco Check 656 14.3 0.808 2.09 398 681 20.8 0.7783 2.3325 400.5 Fert 561 19.0 0.555 1.62 372 757 26.5 0.844 2.7658 362.5 Ash 675 14.8 0.808 1.88 376 608 24.5 0.7895 2.5225 404.3 Ash+N 747 16.3 0.555 1.73 387 827 21.8 0.823 2.5028 400.8 LSD95% 220.0 11.88 0.2045 0.970 101.8 467.4 9.45 0.12719 0.71417 86.12 CV% 20.8 46.2 18.7 33.2 16.6 40.7 25.3 9.8 17.6 13.7

Fig. 5. Multivariate analyses of the community level physiological profiles (CLPP) in rhizosphere soil.

Fig. 6. Multivariate analyses of the community level physiological profiles (CLPP) in bulk soil.