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Midwestern US Conservation Farming Tour - Travelling through the 'corn-belt' of the US



19 September 2011

Together with Andrea Koch, Program Leader of the Soil Carbon Initiative for the United States Studies Centre at The University of Sydney, I had the unique opportunity to join a 'Conservation Agriculture' bus tour across the 'corn belt' of the US with a group of Australian farmers as well as staff from government departments. Throughout the trip the purpose was to make comparisons of the Midwestern US and Australian conservation agricultural systems and also to learn about US agribusiness (e.g. Monsanto Learning Centre Gothenburg, John Deere Combine manufacture East Moline, Martin-Till industries Elkton) as well as to look at conservation farming methods from the science perspective and in particular across different soil types and environmental settings.

The trip was hosted by John Lawrie, soil scientist with the NSW Central West Catchment Management Authority (CMA) who has been organising similar tours to gain insight into the conservation agriculture sector of countries other than Australia since the early 2000s. Most tour participants attended these previous trips and know each other through their association with the NSW Conservation Agriculture and No-till Farming Association (CANFA), an organisation that 'promotes healthy soils and management systems supporting profitable farm businesses, rewarding lifestyles, and a healthy environment' (www.canfa.com.au). The current president of CANFA, Richard Langley from Central NSW, who started conservation farming in 1987, was on tour with us. We were also very fortunate to have Gary Hines, one of the Australian pioneers of no-till farming who started no-till back in the 1963s in WA, and Brian Murphy, established soil scientist with the NSW Office of Environment and Heritage, on board with us. Their insights into conservation farming systems and managed soils were greatly appreciated throughout the trip.

Overall, the trip was thoroughly enjoyed by all participants and has provided us with potential agricultural collaborators as well as diverse, very valuable information on successful conservation agriculture systems occurring in the corn-belt.

In general, the North American prairie soils are very well suited for agricultural production. In contrast to the formation of Australian soils, their formation was directly or indirectly influenced by the last glacial advance on the Northern Hemisphere. The majority of soils were formed on often metre thick loess deposits (eroded, windblown silt material) that buried glacial till, making the Midwestern US soils one of the most fertile regions for agricultural production in the world. From Colorado to Kentucky most soil types belonged to Alfisols or Mollisols in the USDA soil classification system. Topsoil as well as subsoil textures fell into the loam category, with silty and clayey loams the predominant texture type. In general, these loamy soils have good water holding capacities and soil structures that do not impede root growth at depth. In contrast, Australian soils used for agricultural production, are often characterized by a texture contrast, with loamy topsoils over heavy clay subsoils that are often limiting for root growth.

Nevertheless, farmers need to adopt certain farming practices in order to optimise crop production, because of restricting environmental conditions for agricultural production in 'the corn belt'. For instance, the limiting factors for farming in the state of Colorado are low rainfall (350mm annually), topsoil loss through winderosion (winds of up to 70km/hr are common here), and the relatively short length of the growing season. The majority of dryland cropping farmers use the so called 'stripper header' to harvest cereal crops (wheat) instead of a cutterbar header. The 'stripper-header' only strips off the grain to reduce the amount of straw taken into the harvester and leaves standing residue behind instead of a 'thick mat of chopped straw' (www.shelbourne.com). This guarantees a more favourable planting environment and provides a snow trap in winter to conserve moisture as well as acts as a ground shade and reduces windblown soil erosion in a wheat, corn, fallow rotation which is common in the area.

On the other hand, in Iowa and Ohio, farming is impeded by high rainfall (890 and 1016 mm annually, respectively) in the spring which often causes water logging on arable fields. Farmers here deal with this problem by installing a so called 'tile-drainage' system in the subsoil.

For us soil scientists on the trip it was very exciting to come across the 'American fragipan' in Kentucky, a zone of compressed almost cemented silty material in the subsoil that prevents water infiltration and therefore also causes water logging in this region. The genesis of fragipans is still 'under debate', however, in Kentucky, it is believed that fragipans stem from compacted windblown loess material. One practice that is used here to deal with subsoil compaction is to plant deep-rooted Italian Ryegrass to break up the fragipan and subsequently improve water infiltration.

Travelling across the agricultural sector of the various Midwestern states, starting in Colorado, followed by Kansas, Nebraska, South Dakota, Iowa, Illinois, Ohio and Kentucky, one fact became very obvious: Corn is the predominant crop here. One of the American farmers very fittingly used the expression: 'Corn production is King in the US!'. On our tour we mainly passed 'miles' of corn fields, intertwined with fields of soybean and wheat, and open 'North American prairie'. Some of the 'North American Prairie fields' that we passed in Colorado and elsewhere were used for farming at some time in the past but are now part of the CRP, the Federal Government's Conservation Reserve Program. This Program was initiated in 1985 to take cropland out of production in an effort to preserve or restore unmanaged 'native prairie vegetation'. CRP's must be in place over a period of 10-15 years in order to receive rent from the government of $30-35 per acre each year. The farmers opinions were divided on whether the program is beneficial for farming communities since up to 25% of a counties agricultural land can be occupied or 'locked-up' by CRP.

Minimum-till or no-till conservation farming was practiced by all farmers that we visited on our tour. Conservation tillage was introduced in the 1960s to prevent soil erosion, save water, energy, labour and wear and tear on equipment and became possible with the availability of herbicides to manage weeds which were controlled by intensive tillage in distributing the weeds back into the soil. On our tour we visited the region of the acclaimed 'birth-place' of no-till in the US, Herndon Kentucky, where no-till has been practiced since 1962 by the 'Young family'. Nowadays, no-till practises are scientifically known for their potential to increase soil organic carbon (SOC). In recent years, in addition to its benefits for soil quality, plant growth and production, SOC has received increasing attention to play an important role in mitigating atmospheric CO2. On most farms or research stations that we visited, soil quality is not 'measured' by monitoring the amount of soil organic carbon in the topsoil per se. The majority of farmers focus on monitoring the soil water retention, pH, nutrient availability and ground cover (one farmer stated that he does not want to see the soil unless he takes a soil probe). However, there are 'movements' in the area to promote the benefits of 'official' SOC sequestration. For example, we met with Peter Donovan, one of the founders of the soil carbon challenge, a ten year (worldwide) soil carbon monitoring program (http://soilcarboncoalition.org/challenge). Peter calls the program, the next agricultural revolution. On behalf of the soil carbon challenge, he is currently touring the US to promote the benefits of SOC and to take inventory of SOC stocks.

On our tour, we came across no-till farmers who are optimising yields with the help of GM crops and herbicide applications to deal with weeds and insects. On the other hand we also met with farmers who minimised the use of herbicides by introducing diverse rotations and also farmers who were dedicated to 'Biological or Organic farming'. Most farmers were using the newest farming equipment (also an indication that the past years of farming have been very profitable), taking advantage of precision agriculture technologies such as variable application of fertilizers and chemicals based on the spatial variability of the paddock (site-specific information). Controlled traffic systems are also in place.

For instance, in relation to Precision Ag, one farmer, Dietrich Kastens who is the president of the 'Kansas Ag Research and Technology Association (KARTA)' stated enthusiastically that 'It is very exciting, all the science that's coming into farming!'. One of 'KARTA's goals is to 'facilitate on-farm research by providing educational workshops to teach techniques and analysis methods' (www.kartaonline.org), and also to provide a platform for interaction between farmers, academics and industry.

Near Pierre, South Dakota, we met with Dwayne Beck, manager of the Dakota Lakes Research Farm ('The home of regenerative agriculture- healthy food, clean water, living soils, abundant wildlife') which is operated by the Dakota Lakes Research Farm Corporation, a not-for-profit corporation established by 11 farmers in the area and the South Dakota State University (www.dakotalakes.com) in an effort to improve cropping systems and the agricultural economy in the region. The effort worked; farmers in the area agree 'Dwayne Beck has put more dollars into South Dakota's agriculture than anyone else'. Since 1990 research is focused on optimal dryland warm and cool-season crop/broadleaf crop rotations. Rotations are chosen to allow for optimal crop sequence, water management (moisture retention), and to prevent spreading of diseases and weeds. One of Dwayne Becks rotational rules is 'do not be predictive, be smarter than the insects/weeds', therefore 'long breaks are the key' in general allow for a 'two years break for one year in the rotation'.

In Tampico, Illinois, we had the unique opportunity to visit an Amish-Mennonite community who operates 'Midwest Bio-Systems' (www.midwestbiosystems.com), a 'Humus-compost' producer as well as compost making equipment manufacturer (e.g. the 'Aeromaster' compost turner). 'Midwest Bio-Systems' compost 'recipe' contains up to 70% stubble residue (corn/wheat), 20% manure (sourced from their free range chicken operation), and about 10% clay (2:1 clay mineral) which is their 'special' ingredient (plus biological inoculants). The success of their compost mixture is believed to stem from the 'building' of humic substances and stable 'clay-humus' complexes.

No-till farmer Bill Richards who we visited on his farm near Circleville, Ohio, dedicated his farm to demonstrating conservation practices (no-till with residue management) to other farmers in the region. He is using controlled traffic with customized machinery (planters, harvesters) to limit compaction to travel lanes and tramlines which improves the overall surface soil quality in between lanes (e.g. soil texture, water infiltration). Richards and his sons are growing corn and soybean in rotation and also use corn for silage which they distribute to a neighbouring Dairy Farm which in turn supplies manure back to the Richard's farm to use as liquid fertilizer on their fields, a local win-win situation.

We also met with Phil Needham of Needham Ag Technologies who acted as our tour guide, introducing us to Kentucky's conservation agriculture. Phil, who was a guest speaker at CANFA's 2011 conservation farming conference, held in Dubbo a couple of weeks ago, believes in no-till practices that do not involve mixing or the incorporation of residue in the soil. His definition of zero-till practices only involves a single-disk planter that is used for cutting through the soil and crop residue to precisely position crop seeds into the ground and therefore retaining the majority of crop residue on the soil surface (find out more on CANFA's website). Leaving crop residue maximises the moisture availability for the crop and can also act as weed preventer by reducing their emergence with surface mulch in place.

Please visit the United States Studies Centre's website for more information on some aspects of the trip.


Contact: Dr Uta Stockmann

Phone: 02 8627 1147

Email: 333930051c1739142a1b193b05363452315a14094a5216055c031c