Jock McFarlane, Rural Solutions

Transcription

1 "Building Resilient Farming Systems" Jock McFarlane, Rural Solutions Background The Advisory Board of Agriculture and The McKillop Farm Management Group have joined forces to deliver this National Landcare funded project. In the South East the project is concentrated around Bordertown where the aim is to improve water use efficiencies of crops and pasture by reducing the soil constraints that impede root growth. Six trials have been set up to demonstrate improvements that can be made by improving soil conditions in the subsurface profile that encourage root growth. Major advances have been made in the district with clay spreading and delving. However both these methods of soil improvement have their limitations in depth of incorporation and the uniformity of effectiveness at depth. The spader is being used as the basis of the current work. After initial delving or clay spreading further working is possible with a spader which works the clay down to 35cm with more even distribution. The spader incorporates clay, organic matter (hay, silage or green manure) and fertiliser, lime or gypsum to 35cm and leaves a fine fully worked soil in one pass. In the trials the effectiveness of the spader has been compared to clay spreading, delving, ripping and the deep injection of nutrients. The spader was used at 4 sandy sites that had been previously clayed or delved and on 2 heavier loamy soils. Project Work Plan Six demonstration sites have been set up and sown in response to a workshop of representatives of 6 Agricultural Bureau Groups and the Upper South East MacKillop Farm Management Group. These were at: 1. Sherwood at Steven Jaeschke's on a previously delved sand over clay soil approximately 20 cm deep with a bleached sandy layer above the clay. Wheat Treatments replicated 3 times, 10m x 50m: Nil Spaded at 2 depths - 15 cm and 20 cm Spader and organic matter (lupin 110g/L,15 FEL buckets R1, 10 FEL buckets R 2&3). Approximately 12 t/ha on Rep 1 and 8 t/ha on Rep 2 & 3. Spader and fertilizer (200 kg/ha Super + Cu 1% + Zn 1% + Mn 5%) Fertilizer injected to cm Fertilizer spread on surface. 1 farmer attended the treatment application 81

2 2. Lowan Vale at Roger Groocock's on the Landcare site where there is already a great deal of information generated. Previously delved. Barley sown Treatments replicated 3 times, 10m x 50m: Nil Spaded 2009 Spaded 2009 and 2010 Spaded 2010 Spader and organic matter approx 6 tonnes/ha) Spader and fertilizer (200 kg/ha Super + Cu1% + Zn1% + Mn 5%) Fertilizer spread on surface 1 farmer attended the treatment application 3. Willalooka at Gary Lock's on a sand over clay soil approximately 80cm deep with a bleached sandy layer between 20 and 60 cm overlying a yellow sand above the clay. Clay spread with Claymate approx 250 tonnes/ha. 30kg/ha undersown with lucerne Treatments replicated 3 times, 10m x 50m: Nil Spader Spader and organic matter approx 5 tonnes/ha) Spader and fertilizer (200 kg/ha Super + Cu 1% + Zn 1% + Mn 5%) Fertilizer injected to 30 cm Fertilizer spread on surface Ripped to 35 cm 5 farmers attended treatment application 82

3 4. Western Flat at Mal Ramsey's on a sand over clay soil approximately 40 cm deep with a bleached layer above the clay that has been clayed 3 years ago with a approx 250 tonne/ha and has been ripped to 40 cm in Barley Treatments replicated 3 times, 10m x 50m: Nil Spader Spader and organic matter approx 6 tonnes/ha) Spader and fertilizer (200 kg/ha Super + Cu 1% + Zn 1% + Mn 5%) Fertilizer injected to 30 cm Fertilizer spread on surface 50 kg/ha as urea 4 farmers attended the treatment application 5. Paddock 2 on Verco's farm dark red soil sown to oats following spading 83

4 6. Paddock 8 on Verco's farm red sodic soil sown to wheat following spading. Treatments replicated 3 times treatment plots 5m x 50 metres due to spatial constraints: Spader Spader and organic matter approx 5 tonnes/ha) Spader and fertilizer (200 kg/ha Super + Cu1% + Zn1% + Mn5%) Spader and 5 Tonnes/ha Fertilizer injected to 30cm Gypsum spread on surface Fertilizer spread on surface 1 farmer, the High School Ag teacher, 4 year 12 students and 2 SARDI field staff attended the treatment application Monitoring and evaluation Following emergence comparative seeding depth, plant counts and inspection of plant root health and development were undertaken by crop agronomists from Murray Bridge at Jaeschke s and Ramsay s site on 22 nd July. Initial observations at all the sites indicate: The importance of seeding depth control on spaded sites The possible dangers of spading soils with sodic clay in the subsurface profile because of surface sealing and water ponding. Early Nitrogen deficiency where A1 horizon has been buried. Soil and Plant Analysis On 26 th and 27 th August a field day was held at each of the 5 sites to coincide with the soil and plant analysis monitoring. 50 farmers in total attended the field days. They were brought up to date with the progress of the trial areas which were all in the mid to late tillering phase of crop development. 84

5 They were also encouraged to be involved in the soil and plant tissue sampling of the treatments in the crops having discussed the timeliness of monitoring for crop nutrition. At Ramsey s Western Flat site obvious manganese deficiency was diagnosed adjacent to the trial area. This was subsequently supported by the plant tissue analysis. APSIM and Yield For Profit Forum On 22 nd September an APSIM and Yield for Profit Forum was held at the Keith Golf Club. 26 attendees heard CSIRO scientist Anthony Whitbread and Birchip Cropping Group Yield for Profit Consultant Tim McClelland speak about the science behind APSIM and issue the challenge to use the decision making tools generated to make reasoned decisions. Trent Potter also presented data for crop yields in trial work related to the relevant historical rainfall data for those trials. Following the forum 2 sites have had moisture probes inserted and are being monitored by a water use consultant at 3 different levels in crops that are participating in the APSIM and Yield for Profit program. 85

6 October Farm Walks/Bureau Field Days Wirrega/Lowan Vale Bureau and the Upper South East MacKillop Group hosted their field day on 26 th October and was attended by 20 farmers. Jaeschke s site at Sherwood and Groocock s site at Lowan Vale were included in the visits Western Flat Agricultural Bureau held their field day on 4 th November with 18 farmers attending. Highlights of the day were seeing a 10 t/ha vetch crop spadered into the ground as a green manure crop in preparation for a potato crop in 2010 and the site at Ramsey s Mundulla Agricultural Bureau held their field day on 6 th November. 12 farmers visited the sites at the High School where plots had been mown for vegetative yield determination because of the crop failure. Harvest 3 of the 6 sites had crop failure or were reaped by farmer machinery. These sites have been mown and drymatter yields determined for analysis. 86

7 Jaeschke Sherwood Harvest Wheat 2009 (kg/ha) Entry kg/ha % site mean Spader Spader Spader + fertiliser Injected fertiliser Spread fertiliser Spader + Organic matter Nil Site mean 2734 CV% 6.99 lsd(0.05) The spader + organic matter treatment looked significantly better than other treatments during the growing season but with the heat of early November the vegetative growth was not reflected in grain yield. Ramsay Western Flat Harvest Barley 2009 (kg/ha) entry kg/ha % site mean Spader + Fertilizer Spader Nil Fertilizer Injection Fertilizer Spread Spader + Organic Matter kg Urea Site mean 3205 CV% 6.7 lsd(0.05) 374 Soil analysis (0-10 cm) would suggest that the organic layer built up under long term pasture has been dispersed throughout the profile and with the low fertility status of the site the grain yield on the spadered treatments, even with added fertilizer, was less than the undisturbed treatments. The exception was the spadered treatment with organic matter which grew significantly more vegetative growth during the season and followed through with extra grain. 87

8 Groocock Lowan Vale Harvest Wheat 2009 (kg/ha) entry kg/ha % site mean Nil Spader Spader 2009 and Spader + Organic Matter Nil 2009 spader Fertilizer Spread Spader + Fertilizer Site mean 4363 CV% 6.94 lsd(0.05) This site has a very good fertilizer history and soil analysis from samples taken in August show no difference between the different treatments all the nutrients in the adequate range. Plant analysis confirmed this, with the only nutrient being in the marginal range being manganese. Lock Willalooka Barley stubble and lucerne Dry matter 21/12/09 entry kg/ha % site mean Spader + Fertilizer Spader + Organic Matter Spader Fertilizer Injection Fertilizer Spread Ripped Nil Site mean 2342 CV% 14.7 lsd(0.05) The trial results are presented as drymatter harvested because the barley was harvested with the paddock. The spader + fertilizer and spader + organic matter treatments indicated a vegetative response during the growing season. The site was spread with around 100 ton of clay prior to spading, which may explain why there was not a reduction in yield with the spading treatment which may have been expected with the surface organic matter layer being buried and associated nutrition of the soil being diluted. 88

9 Bordertown High School - paddock 2 Oats and ryegrass Dry matter 6/11/09 entry kg/ha % site mean Nil Gypsum Spread Fertilizer Spread Spader + Fertilizer Spader + Organic Matter Spader Fertilizer Injection Spader + Gypsum Site mean 4100 CV% lsd(0.05) 785 The soil type at the High School farm is a red/brown loam over clay with an increasing level of sodium. At the seasonal break, the soil was only wet to around 10 cm when the site was spaded. This was not ideal and the spader broke a number of chains on the rear roller. Because of the breakdowns the seeding was interrupted and there was patchy emergence and crop growth. The gypsum treatments should have both been responsive with the sodic nature of the underlying clay. Bordertown High School - paddock 8 Wheat and ryegrass Dry matter 6/11/09 entry kg/ha % site mean Spader Spader + Organic Matter Nil Spader + Fertilizer Fertilizer Injection Spader + Gypsum Fertilizer Spread Gypsum Spread Site mean 5483 CV% lsd(0.05) 971 Similar difficulties were encountered with this site as for the other High School Site. Irrigation Area Sampling The soil sampling program has continued at Fry s. This was particularly valuable as it was the first sampling undertaken in the program where near normal winter rain helped flush accumulated salt down the profile under the pivot irrigation system. 89

10 Publications and Extension 2 publications have been produced with funding from the program: Bailey, G. (2009) Soil Water compendium an identikit for determining your soils water properties. The Soil Book Representative soils of the Upper SE In addition 4 press releases highlighting the project and activities have been picked up by local newspapers and gone to air on local radio. The project and its progress was discussed at a SE NRM meeting where project officers from a number of soils related projects being undertaken in the South East met to see what alliances and cooperation could result from being aware of the other work undertaken in the Region Program The work program next year will continue to monitor the sites already established, with similar activities planned. More emphasis will be placed on the water use efficiencies associated with the individual treatments. 1 year after site establishment with some equilibrium reached in the treatments after initial working, soil carbon will be measured. One new site will be established on the black clay soil type in the district, where the emphasis will be on controlled traffic, trace elements and soil carbon. 90