Sugarcane Soil Sampling Procedure

Transcription

1 Sugarcane Sil Sampling Prcedure WHY SOIL SAMPLE? The answer t this questin shuld guide the way a sample is taken. Sil sampling and analysis is a valuable Nutrient Advantage tl, prviding insight int the nutrient and general fertility status f surface (and if analysed, sub-surface) sil layers. Sil analysis is nrmally undertaken fr ne f three reasns. These are:- Predictive - t check n the sils fertility r nutrient status, t better determine r predict nutrient requirements; Mnitring - t assess the suitability f current management practices ver time, adjusting existing fertiliser prgrams if necessary t ensure ptimum yields are achieved; r Diagnstic - t determine the reasn fr pr grwth (truble-shting), r t check n accumulatin f mineral elements txic t plants. The end result, and perhaps prime bjective, is t arrive at a fertiliser recmmendatin tailred t the individual requirements f each prductin system. The benefits f sil sampling t the farmer are: Establish the current nutrient status f the sil t prvide the basis fr future strategies. Indicate the amelirants required t crrect a sil s pssible physical and chemical prperty imbalances. Determine factrs that may be limiting crp and pasture prductin. Identify pprtunities t imprve farm prfitability thrugh efficient sil fertility management. Develp an apprpriate nutrient plan fr the farm based n prductivity targets. Mnitr the prgress f nutrient strategies ver time and indicate any need t fine-tune inputs. Determine the better fertiliser frm &/r applicatin methd t suit particular situatins. Assists in the planning prcess thrugh imprved budgeting f farm financial resurces. These benefits may result in better farm management thrugh mre cst effective nutrient decisins. WHAT YOU WILL NEED SOIL SAMPLING EQUIPMENT Clean cre sampler (prbe) t cllect tpsil samples Screw driver and clean plastic bucket t remve and cllect sil frm the sampler Small spade t remve any excessive debris Small hand auger fr subsils Hydraulic sampler t cllect deep sil nitrgen samples Sample cllectin bag, Submissin Frm, plastic pcket all available frm the Nutrient Advantage Help Desk n r yur lcal Incitec Pivt Agent r Dealer. Cre maintenance equipment such as a cleaning brush, silicn spray Make sure t clean the prbe with a brush after use and give the prbe a light spray inside and ut with silicn spray t prevent rust befre being stred.

2 2 SAFETY WITH SAMPLING Sampling invlves physical wrk in the utdrs. A cmmn sense apprach is required, as fr all wrk n farm, with due cnsideratin t: Expsure t the elements, including the sun. Wear apprpriate clthing, a hat, and sunscreen during the summer mnths, stay hydrated Sampling near hazards eg high vltage / gas lines / cmmunicatin cables Paddck/blck hazards including electric/barbwire fences, steep grund, pt hles, wet grass, channels/drains; Observe re-entry perids in crps that have been sprayed with pesticides, e.g. insecticides; Wash yur hands between taking different samples, and befre eating; Keep yur back straight when taking sil samples and during lifting peratins; Be aware f the presence f and n the lkut fr farm animals, e.g. dgs, bulls, and native fauna, e.g. snakes, and maintain apprpriate distances. Make sure yu have First Aid Kit available. A NOTE ON QUARANTINE Nutrient Advantage Labratry is nt an AQIS Apprved Premises and therefre we d nt accept quarantine sil samples. In the case f dmestic quarantine samples, the nus is n the submitter t make sure a sample is nt frm a quarantine risk area r has the apprpriate permit when submitted t the Nutrient Advantage Labratry. Dmestic samples shuld cmply with the Department f Envirnment & Primary Industries Plant Quarantine Manual which can be fund n T keep up t date with State Quarantine risks g t the Quarantine Dmestic website T btain a permit fr the remval f sil material frm a quarantine risk cntrl area cntact Department f Envirnment & Primary Industries, Victria n All Quarantine samples despatched t the Labratry shuld be accmpanied by the relevant AQIS r State Permit dcuments and Irradiatin Certificate (if required in line with the Plant Quarantine Manual guidelines) tgether with the apprpriate sample submissin paperwrk fr analysis. COLLECTING A SOIL SAMPLE Establish apprpriate sampling prgram (see Sectin A belw) Ensure the Sample Submissin Frm is fully cmpleted. The crrect sampling and handling prcedures must be fllwed (see Sectin B belw). Accurate infrmatin is essential. Nutrient recmmendatins are nly as gd as bth the quality f the representative sample taken and the detail f the assciated sample infrmatin supplied.

3 3 WHAT IS A REPRESENTATIVE SOIL SAMPLE? A representative sample cnsists f a large number f sil cres taken frm within a unifrm area f a sil type r paddck f cncern. Fr surface samples (0-20cm), it is imprtant that at least 25 t 30 cres be taken. It has been prven that samples, made up f less than 20 cres, ften d nt crrectly represent the sampled area. If a sample is taken frm a large area (say 15 r mre hectares), it is ften advisable t take mre than 40 cres, t make-up ne sample. If the cllected cres exceed apprximately 500 grams in weight, they shuld then be mixed thrughly tgether and a representative subsample is taken, t send t the labratry. If the cllected cres are apprximately 500 grams in weight, they can be sent t the labratry withut the need fr sub-sampling. The sampling depth reflects that used when the field calibratin f sil tests were cnducted by the researchers. Fr sub-sil samples (20-60cm), 8-10 cres will usually suffice, as subsils typically shw less variability than surface sils.

4 A. SOIL SAMPLING STRATEGY FOR THE BLOCK 1. In Great Barrier Reef catchment areas, prir t initiating any sil testing r nutrient recmmendatin fr sugarcane, refer t the details utlined at the website: 4 The sil sampling prtcls utlined within this website is cnsidered the minimum requirements t satisfy the legislatin. IPL strngly advcate fllwing the mre thrugh sampling prtcl as utlined in Sectin B belw. 2. Categrise yur plant cane blcks int sil type & management znes e.g. amelirant histry, mill-by prduct applicatin, fallw management, pr/gd, black/red, sandy/clay. 3. Sample blck/s & sil type/s that will prvide the mst useful interpretatin (eg this culd be the mst dminant sil type r an area where crp prductin is currently belw expectatin). 4. Fallw plant Sugarcane sils have traditinally been sampled at the end f a fallw, r just prir t ne f the final cultivatins befre planting the blck. Hwever sampling at the start f the fallw r either just after harvesting the final ratn is a valid ptin als. Sampling at this time is beneficial as it will allw fr: an earlier assessment f amelirant requirements (e.g. lime, dlmite, gypsum r calcium silicate) requirements; if a fallw crp is t be grwn, a determinatin f nutrient &/r amelirant requirements can be identified; if a green cane trash blanket (GCTB) is t be incrprated int the sil, sampling shuld ccur prir t the GCTB incrpratin. This is t limit the artificial & shrt term increase in Organic Carbn (OC%) due t the recent GCTB sil incrpratin. Because sugarcane nitrgen rates, under the Six-Easy- Steps guidelines, are primarily determined by District Yield Ptentials & the sil Mineralisatin Index. This cultural practice may artificially alter the crp s nitrgen requirement, due t the shrt-term increase in sil rganic carbn levels by incrprating the GCTB and withut sufficient time fr decmpsitin. Just as significantly, if sil samples are cllected whilst the lcatin f last ratn crp s rws are still knwn, a much mre representative and valid fertility status f the sil (especially fr phsphrus) will determined if the fllwing equatin is utilised. Sampling sils in fields under rw-crps r permanent beds can give misleading results. Where the lcatin f the fertiliser band is knwn, the mst representative sample cnsists f S number cres cllected n the fllwing basis: S = Fertiliser Band Spacing (cm) x where S is the number f sil cres taken between the fertiliser bands, fr every ne sil cre taken in the fertiliser band Reference: 'Sil Analysis: an Interpretatin Manual' (1999). Ed's K.I. Peverill, L.A. Sparrw and D.J. Reuter. (CSIRO Publishing: Melburne). 5. Plugh-ut Replant (PORP) - Sil samples taken in plugh-ut replant blcks and are best taken immediately the harvest is cmpleted and befre the sil is cultivated. This assists in getting a representative sample frm an undisturbed sil prfile, as per the details utlined immediately abve.

5 5 B. SAMPLING PROTOCOL Surface Sample Depths cres (minimum) Vic NSW Qld/NT SA WA Tas 0-20 cm 0-20 cm Subsil Sample Depths 8-10 cres (minimum) Vic NSW Qld/NT SA WA Tas cm cm Each sample shuld cmprise a minimum f 500 grams f sil. Examples f varius sampling strategies & their characteristics. Zne A. C. This design is used fr changes in sil types and trends acrss sampling areas (precisin farming). Samples are taken frm each zne and analysed separately. This design shuld be adpted in all sampling strategies, and shuld utilise ne f the sampling methds belw. Zigzag If care is taken this prvides gd cverage f the sampling area, making it the ideal design fr diagnstic sampling. The degree and type f bias vary with experience f peratr. Generally use n areas less than 10ha. Transect Spt samples are taken at regular intervals alng a defined transect. This design allws the same r different peratrs t repeat the sampling with gd precisin. Transect sampling is the simplest sampling methd as the same sample line can be used each seasn fr mnitring fertility trends. Cluster This design invlves sampling arund several pints within a sampling area. Where sampling pints are defined (dgps r pltted n map), cluster sampling can prduce lw variability. Hwever, the results are less likely t be representative f the sampled area. Grid This design is systematic, with individual samples taken at regular intervals acrss the sampling area and analysed separately. It is used in precisin farming and can help vercme landscape r yield variatin, particularly if there is a trend acrss the sampling area. This design can be expensive if many sampling pints are defined.

6 6 B. SAMPLING PROTOCOL (cntinued) 1. Using the crer/auger, take sil sample cres and remve trash/grass and ther debris. 2. Place the cres int a clean bucket and break sil int small crumbs. 3. Mix sample thrughly by tipping sample back and frth between tw buckets, r by mixing n a plastic sheet (avid using hands unless glved). 4. Use a separate, pre-labelled bag fr each sample. 5. After filling with sil, securely seal the bag with the press seal. 6. Areas that shuld be sampled separately are: Different sil types, tpgraphy r blcks. Areas that have been management differently i.e. used varying crpping practices, had amelirant, mill by-prduct, r fertiliser applied differently. 7. Avid unusual areas such as: Very wet cnditins, stck tracks, windbreaks, fertiliser dump sites r headlands. Areas within 20 metres f fence lines, gates, dams, trughs r trees. 8. Areas that have been fertilised r limed shuld nt be sampled until a minimum f 8 weeks has elapsed since applicatin. GETTING THE SAMPLE TO THE LABORATORY 1. Ensure that yu have 500 grams f sil per sample in each bag. Extra sil is used during preparatin time at the labratry fr flushing grinders t avid cntaminatin. 2. Fill ut the apprpriate submissin frm making sure t supply the crrect custmer accunt number. 3. Fill ut ONE Frm fr a maximum f three samples taken frm the same paddck r with the same histries. These samples can be all tpsils, deep sil nitrgen tests r subsils, r a cmbinatin f these test ptins. 4. Ensure a test cde is clearly indicated using the current Nutrient Advantage Price List. 5. Duble check that the barcde numbers n the cmpleted Submissin Frm match the barcde numbers n the sample bags (remember t keep ne fr yur recrds). 6. Remember that yu must supply accurate infrmatin s that crrect interpretatin and recmmendatin f test results can be made. 7. Place all submissin Frms in the clear press seal plastic pcket prvided. Place the submissin frm and sil samples int a Freight satchel and seal deliver t: Attn; Sample Preparatin Nutrient Advantage Labratry 8 Suth Rd Werribee Victria Australia 3030

7 7 SUMMARY Sil testing, results in better infrmatin abut nutrients and sil amelirants which leads t mre effective farm management decisins being pssible. T ptimise this utcme, it is imprtant that the sil sampling strategy is carefully planned and the technique accurately implemented. Remember, the sil analysis results and recmmendatins are nly as gd as bth the representativeness f the riginal sampling technique and the level f detail in relatin t infrmatin prvided abut the sample t the labratry. Fr mre infrmatin abut Nutrient Advantage please cntact the Nutrient Advantage Help Desk n Submissin frms, sil bags, freight bags and ther materials required fr sampling are available frm the Nutrient Advantage Help Desk r frm yur lcal Incitec Pivt Agent. Submissin Frms and current Nutrient Advantage prduct infrmatin are available n ur website. A shallw sample cre type Sampling prbe. A deep sample auger type Sampling prbe.