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1 UK BIOCHAR CONFERENCE 2011 Tite :The Effect of Biochar and Stover Amendment on Soi Physica Environment and Pant Growth Emmanue Dugan Anne Verhoef Steve Robinson Saran Sohi 3 rd Annua UK Biochar Conference: Edinburgh; University of Edinburgh : May 2011 Presentation Outine Introduction Research Rationae Hypothesis & Objectives Methodoogy Resuts and Discussion Concusions Acknowedgments

2 Introduction Biochar = Pyroysis of bio-mass or char-ring biomass Figure 1. Biochar production and appication cyce Credit: Internationa Bio-char Initiative (IBI). Research Rationae Lack of research on biochar mechanisms in Ghana Expore possibiity of improving soi productivity most sois are acidic high rainfa, high temperature, ow OM content ow water avaiabiity other soi amendment practices not yieding expected resuts Feedstock for biochar in abundance and causing nuisance, and eft to decompose reeasing CO 2 into the atmosphere

3 Hypothesis & Objectives Hypotheses: Biochar amendment - improves soi water hoding capacity; - improves crop yied by improving soi physica properties & environment; - using charred maize stover is a better nutrient & environmenta management option than using the raw materia as much. Hypothesis & Objectives conti. Objectives are to evauate: - the effect of partice size of feedstock and charring temperature on biochar quaity and quantity; - how biochar amendment affects the soi physica environment: a) water hoding and transport properties, and radiative properties (such as abedo and emissivity) and b) test the infuence of these changed properties on key soi variabes such as soi/surface temperature and soi moisture content;

4 Hypothesis & Objectives conti. Objectives are to: - evauate the roe of soi texture in improving crop productivity through biochar amendments and - compare effects of charred and un-charred maize stover amendments. Methodoogy Soi samping Coection of biochar materias Ejura Heap of sawdust Heap of maize stover Map of Ghana showing study areas and ecozones Charcoa made in Ghana

5 Methodoogy conti. Charing maize stover and sawdust using muffe furnace (Braadbaart and Pooe, 2008) - LHR (from ambient temperature ~ 20 o C) - HHR (furnace preheated to 100 o C for maize stover) - Sawdust sieved to partice sizes of <0.5 (a), (b) and >2mm; charred at LHR (a) (b) (c) Sieved sawdust; (a) <0.5mm, (b) 0.5-2mm and (c) >2mm Methodoogy conti. Chemica anaysis of charred maize stover, sawdust and sois amended with biochar - Inductivey couped pasma - optica emission spectrometer (ICP- OES) for eement such as Ca; Mg; K; P; Fe; A; etc. - For tota nitrogen (N); Europa Roboprep, connected to a VG 622 Mass Spectrophotometer - LECO SC -444 Carbon Anayser, for tota carbon (C) - ph meter for ph of sois amended with biochar

6 Methodoogy conti. Determination of water hoding capacities of sois, and amended with biochar at 0, 5, 10 and 15 t/ha. - biochar amended and contro sois were saturated by capiary action and drain for 24 hours and determine the gravimetric moisture content. Resuts and Discussions!"! " #$%&'( )* ) +,,- $.( "!± ± "± '/0$/1 2 (!!± "!±"! ""± 34$5 2 ( ±" ± ±! 3$1 2 6, 7 ( ± "± "± 6$( ± ± ± *489$1/1 2 ( ± ±" ± -18$1/1 2 ( ± ± ± $1/1 2 ( """"±" ±!!± :1$1/1 2 ( ± "!!±" " ±" ;$1/1 2 (! ±!!!"± ± $1/1 2 ( ""±!!! "± "± 6, 7 26$1/1 2 ( ±! "! ± " ±

7 Resuts and Discussions Effect of temperature, partice size and heating rate on some physica properties and yied of biochar - Shrinkage and coour Sawdust charred at different temps Nitric acid digested maize stover at different temps Resuts and Discussions conti. Two heating rates (LHR & HHR) No significant difference was observed b/n HHR and LHR at the fina temp 420 o C + $ ( ' $<(## +=#< Three sizes of sawdust Smaest partice size showing highest yied Maize stover yied more than sawdust possiby due to higher concentration of eements " "" "! "" "!! ""! " 2 2

8 Resuts and Discussions conti. Eementa Composition Maize stover % increase in C ( HHR; 48.23% & to % LHR %). No difference was observed between LHR and HHR (p = 0.221). Simiar observation with N, but decined after 360 o C. Thus, increase in C/N ratio; Fe highest increase in conc. (~8 fod) ; Lowest is K (~2) ; Conc. of Ca and P at LHR>HHR (p = 0.046, 0.004). Pooed data aso suggest that Mg, K and Fe had significanty higher concentration at LHR than at HHR. Resuts and Discussions conti. Eementa composition - Sawdust (2 partice sizes P1 and P2 at 450 o C) - Trends for C & N simiar as in maize stover - Conc. of Ca, Mg and Fe b/n P1 and P2 were different P1>P2; (p=0.02, 0.05 and respectivey) Variation of Mg and Fe concentration versus temperature at P1 & P2 partice sizes

9 Resuts and Discussions conti. Effect of the three biochar on soi ph Generay ph increased but varied with soi and biochar materia. Sawdust biochar had no effect on ph of soi A Resuts and Discussions conti. Effect of three biochars on WHC of three sois WHC increased in a sois at 5t/ha, with a three materias; Water repeency possibe at rates higher than 5t/ha or soi structure might be affected negativey; Sawdust and maize stover have highest Increase for soi E ( 79% Sand); Charcoa decreased WHC after 5t/ha in soi E; hydrophorbicity might be responsibe Soi texture diff ce was obvious

10 Concusions LHR deays ateration of origina biomass structure. However, there was no difference in biochar yieds at the fina temperature of maize stover, 420 o C; Biochar yieds differ from the feedstock used due to differences in eementa compositions; There was not enough evidence to suggest that LHR favours C recovery despite a higher % of C retained at LHR than at HHR; Biochar increased in C/N ratio at the fina temperature. Thus, appication to soi wi improve soi C/N ratio; LHR favoured Ca and P concentrations at 420 o C. Thus, therma stabiity of eements is affected by heating rate; Concusions conti. Sawdust sieved with 0.5 mm diameter sieve resuted in higher biochar yied than 2.0mm sieved partices; Eements behaved differenty or simiary at a given partice size of the sawdust; Soi ph generay increased with biochar appication. Magnitude depends on soi and biochar materia;

11 Concusions conti. WHC increased when biochar was appied at 5, 10 and 15 t ha -1, compared to zero rates; The magnitude of WHC improvement varied from feedstock; Improving WHC by biochar was more effective in sandiest textured sois; However, some feedstock may have hydrophobic substances whose effect may be fet more for a different soi texture and at rates higher or ower than 5 t ha -1. Data on moisture retention characteristics and fiedwork are being anaysed. Acknowedgements Commonweath Schoarships Commission of the UK, for funding this project; CSIR-SRI, Ghana, for granting me study eave and Your presence and attention.