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1 29/09/2015 ISSUE 39 UITGAWE 39 NUUSBRIEF / NEWSLETTER Inside this issue: Inhoud: Soil carbon 2 Plant-soil interaction Nuus/News BLWK week 6 Hallo Almal Terugvoer 8 Feedback 9 Competition 10 Ek kan nie glo dit is al die einde van September nie. Die jaar het verby gevlieg. Dankie aan almal wat bygedra het tot ons 3de suksesvolle bewaringslandboukonferensie. Dit word opreg waardeer. Sterkte met die oes ons dink aan al ons produsente in hierdie tyd. Groete van huis tot huis Johann Strauss Moontlike toer 11 Hello All Upcoming farmers days and events: 2016 conference practical day 2 August 2016 conference lecture day 3 August It is incredible to realise that the end of September is insight, it is amazing how quickly the year has flown by. Thank you to everyone that contributed to a successful third conservation agriculture conference, it is much appreciated. Good luck for the harvest season that lies ahead. Regards Johann Strauss

2 P a ge 2 Soil carbon - can it save agriculture s bacon? Christine Jones, PhD Founder, Amazing Carbon Adapted The financial viability of the agricultural sector, as well as the health and social wellbeing of individuals, families and businesses in both rural and urban communities, is inexorably linked to the functioning of the land. There is widespread agreement that the integrity and function of soils, vegetation and waterways in many parts of the world landscape have become seriously impaired, resulting in reduced resilience in the face of increasingly challenging climate variability. Agriculture is the sector most strongly impacted by these changes. It is also the sector with the greatest potential for fundamental redesign. The most meaningful indicator for the health of the land, and the long-term wealth of a nation, is whether soil is being formed or lost. If soil is being lost, so too is the economic and ecological foundation on which production and conservation are based. Carbon trading in the real world For some time, analysts have tipped carbon to become the world s most traded commodity. The reality is that it has been the world s most traded commodity for millennia. A great variety of life forms require liquid carbon - referred to in the scientific literature as dissolved organic carbon (DOC) - for their growth and reproduction. The growth of trees, crops and pastures, for example, requires the transport of dissolved carbon via sap within the plant; animal growth is dependant on the digestion of carbon containing foods and the transport of dissolved carbon to cells via the blood; the formation of topsoil is dependent on photosynthesis and the transport of dissolved carbon, via a microbial bridge, from plants to soil. Carbon is the currency for most transactions within and between living things. Nowhere is this more evident than in the soil. Here, carbon is king. Mycorrhizal fungi, which are totally dependant on liquid carbon from green plants, trade this carbon with colonies of bacteria located at their hyphal tips in exchange for macro-nutrients such as phosphorus, organic nitrogen and calcium, trace elements such as zinc, boron and copper, and plant growth stimulating substances (Killham 1994, Leake et al. 2004). By means of an extraordinary physiological process known as bidirectional flow nutrients are transported to roots at the same time as liquid carbon moves through fungal hyphae in the opposite direction (Killham 1994, Leake et al. 2004). Indeed, mycorrhizal roots are significant sinks for carbon, transferring as much as 15 times more carbon to soil as adjacent nonmycorrhizal roots (Killham 1994).

3 P a ge 3 Impoverishment of agricultural soils Mycorrhizal fungi and associative bacteria are very strongly inhibited by excessive soil disturbance and the high levels of water-soluble phosphorus and nitrogen commonly used in modern agriculture (Killham 1994, Leake et al. 2004). Where soils have been subjected to cultivation and/or the application of MAP, DAP, superphosphate, urea or anhydrous ammonia, the suppressed mycorrhizal colonisation of plant roots significantly reduces carbon flow. The structural degradation of agricultural soils, accompanied by mineral depletion in food, has largely been the result of the inhibition of this natural carbon pathway. When carbon supply is limited by the loss of the primary pathway for sequestration, the physical, chemical and biological functions normally performed by healthy soil are markedly reduced. Soil carbon and soil moisture In addition to enhancing nutrient availability, carbon performs many other functions in soil, including the maintenance of soil porosity, aeration and water-holding capacity. Glenn Morris (Morris 2004) extensively researched the water holding capacity of humus (an extremely stable form of soil carbon) and concluded that within the soil matrix, one part of soil humus could, on average, retain a minimum of four parts of soil water. From this relationship it can be calculated that an increase of 16.8 litres (almost two buckets) of extra plant available water could be stored per square metre in the top 30 cm (12 ) of soil with a bulk density of 1.4 g/cm3, for every 1% increase (in absolute terms) in the level of soil organic carbon. This equates to 168,000 litres of water that could be stored per hectare, in addition to the water-holding capacity of the soil itself (Jones 2006). The flip side is that the same amount of water-holding capacity will be lost when soil carbon levels fall. Low soil moisture and low levels of soil organic carbon go hand in hand. Soil organic carbon levels in many areas have fallen by at least 3% (in absolute terms) since the time of European settlement, This reduction in soil carbon content represents the LOSS of the ability of soil to store around 504,000 litres of water per hectare. Soil carbon and soil nitrogen Aside from water, nitrogen is frequently the most limiting factor to crop and pasture production. It is one of the great ironies of agriculture that the atmosphere is around 78% nitrogen, but not one single molecule is directly available to plants. There are approximately 78,000 tonnes of nitrogen gas sitting above every hectare of land. Apart from small accessions via lightning, this nitrogen cannot be accessed without a microbial bridge. Most nitrogen-fixing bacteria - be they free-living in the rhizosphere, confined to nodules on plant roots, contained in aggregates bound by the hyphae of mycorrhizal fungi - or existing as endophytes in plant leaves or stems - derive their energy from liquid carbon fixed during photosynthesis. Adding water-soluble nitrogen in the form of urea, anhydrous ammonia or nitrate, destabilizes the plant-soil ecosystem by reducing the activity of mycorrhizal fungi and free living N-fixing bacteria (Killham 1994). The presence of high levels of water-soluble nitrogen in soil sends a signal to plants to reduce the supply of liquid carbon to microbial symbionts, effectively inhibiting the microbial associations that would otherwise supply atmospheric nitrogen for free. This contradicts the widely promoted belief that nitrogenous fertiliser must be added in order for stable soil carbon to form. Indeed, the opposite is true (Khan et al. 2007, Larson 2007, Mulvaney et al. 2009).

4 P a ge 4 Soil test data show that as soil carbon levels increase in microbially active soils, availabilities of P, K, S, Ca, Zn and B commonly increase, while levels of nitrate nitrogen are often reduced. If plants are mycorrhizal, they don't require nitrogen in a mineralised form, that is, in the form of nitrate or ammonium. In order to transport mineralised nitrogen, mycorrhizal fungi must first convert it to glutamate, a process which represents an energy cost. For this reason, nitrogen is preferentially transported in an organic form, generally as amino acids such as glycine and glutamine (Leake et al. 2004). Utilisation of organic nitrogen by mycorrhizal fungi closes the nitrogen loop and prevents soil acidity, as well as preventing volatilisation of nitrogen to the atmosphere and leaching to aquifers, rivers and streams. Changes to soil chemistry and nitrogen dynamics in microbially balanced soils also reduce the abundance of weedy species such as annual ryegrass, capeweed, mustard weed and thistles. The germination of these species is stimulated by the ready availability of nitrate nitrogen. Soil carbon and human health The nutritional status of soils, plants, animals and people has fallen dramatically in the last 50 years, due to losses in soil carbon, the key driver for soil nutrient cycles. Soil health and human health are more deeply connected than many people realise. Food is often viewed in terms of quantity available, hence food scarcity is not seen as an issue. However, food produced from depleted soils does not contain the essential trace minerals required for the effective functioning of our immune systems. The low nutritional status of many basic food items is highlighted in data from the UK. Depletion in the level of minerals in vegetables for the period , for example, shows copper levels reduced by 76%, calcium by 46%, iron by 27%, magnesium by 24% and potassium by 16% (Thomas 2003). Deficiencies in plants translate through to deficiencies in animals. A piece of steak now contains only half the amount of iron that it would have contained 50 years ago (Thomas 2007). Vitamin and mineral deficiencies in food indicate that the symbiotic relationship between plants and soil microbes, whereby minerals are exchanged for liquid carbon, has been disrupted. The best national health policy would be a national soils policy. But we don t have one.

5 P a ge 5 Understanding plant-soil interaction could lead to new ways to combat weeds Adapted from ScienceDaily Using high-powered DNA-based tools, a recent study at the University of Illinois identified soil microbes that negatively affect ragweed and provided a new understanding of the complex relationships going on beneath the soil surface between plants and microorganisms. "Plant scientists have been studying plant-soil feedback for decades," said U of I microbial ecologist Tony Yannarell. "Some microbes are famous for their ability to change the soil, such as the microbes that are associated with legumes -- we knew about those bacteria. But now we have the ability to use high-power DNA fingerprinting tools to look at all of the microbes in the soil, beyond just the ones we've known about. We were able to look at an entire microbial community and identify those microbes that both preferred ragweed and affected its growth." Although it would seem that the logical conclusion would be to simply add anti-ragweed microbes to soil, Yannarell said that adding microbes to soil hasn't been successful in the past. An effective strategy, however, to suppress weeds might be to use plants that are known to attract the microbes that are bad for ragweed, and in so doing, encourage the growth of a microbial community that will kill it. The study used Manhattan, Kan. (sunflower) and Urbana, Ill. (ragweed) and conducted trials independently at agricultural research facilities in Michigan, Illinois, Kansas, South Dakota, and Oregon, using local soils gathered on site. These particular weeds were selected because ragweed is a more common weed east of the Mississippi and sunflower is more common in the West. The experiment allowed Yannarell and his colleagues to observe how three generations of ragweed and sunflower interacted with the microbial community in the soil. The plants interact with each other indirectly due to the differing effects they each have on the microbes in the soil. "We used the same soil continuously so it had a chance to be changed," Yannarell said. "We let the plants do the manipulation." Interestingly, they did not find the same ragweed-preferring microbe across all five states. "The microbial communities are different in each of these states, and yet we found the same overall patterns in each state individually," Yannarell said. Illinois, Oregon, Kansas, and South Dakota (and in about 50 percent of the data from Michigan) each had local microbes that preferred ragweed and had a negative effect on its growth. "That was a take-home lesson for me," he said, "that the actual organisms can be different in different locations, but they still may be performing the same functions." Yannarell said that currently one of his graduate students is studying ways to use what they learned as a method for weed control. "What we're looking at now is the use of different cover crops, many of which are not harvested but just turned under into the soil," he said. "We're looking for specific cover crops that can make the microbial community bad for weeds as opposed to spraying. Can we create weed-suppressive soils?"

6 P a ge 6 Bewaringslandbou Konferensie week 2015 n oorsig Johann Strauss 2015 was die derde keer wat die bewaringsweek aangebied is. Vanjaar is die week eers in September aangebied na n versoek van LandCare om n gesamentlike week aan te bied. Twee parallelle sessies is aangebied gedurende die week en kon belangstellendes kies wat hulle wou bywoon. Terugvoer oor beide programme was oorwegend positief en is ons dankbaar vir al die belangstelling. Volgende jaar se bewaringsweek sal weer in Augustus aangebied word. En beloof om nog beter te wees. Ons gaan vroeg datums deurgee vir al die groen en bruintoere asook die bewaringsweek sodat julle dit kan vaspen op julle kalenders. Die twee praktiese toere 2015 Die bywoning vir die twee dae was goed en het sowat 80 mense die twee dae mee gemaak. Beide toere het interessante besoekpunte bevat en is daar lekker met die twee besoekende Aussies gesels oor verskillende aspekte van bewaringslandbou soos dit hier beoefen word in vergelyking met die situasie in Suid-Australië. Een opmerking wat beide besoekers teenoor my gemaak het was hulle verbasing oor ons beheptheid met klippe. Beide Tom en Greg gaan vir ons nog terugvoering gee oor wat hulle ervaar het tydens hulle besoek en dit sal dan in die nuusbrief verskyn. Die Konferensie dag Die dag het baie goed afgeloop en het ons baie geleer in terme van die gebruik van skyfplanters en die opstelling daarvan en iets wat ek my denkwyse oor verander het. Ek moet bieg ek was onder die indruk dat ons eers met tandplanters moet werk vir n tyd om ons grond te kondisioneer, alvorens ons skyfplanters oorweeg. n Skyfplanter kan van die begin af gebruik word, dit moet net reg opgestel word om optimaal in ons toestande te werk. Mense mag van my verskil en dit is goed so, ek dink net ons moet n slag voentoe kyk na waar ons wil wees en nie net vas kyk in wat ons as probleem sien nie. Die sprekers se praatjies is almal op video vasgevang en sal met die verloop van tyd beskikbaar gestel word op ons webtuiste. Weereens dankie aan almal wat die dag moontlik gemaak het. Dankie aan al ons borge, sonder julle sal ons nie so n lekker dag kon aanbied nie. Dankie aan elke produsent en al die mense uit die bedryf wat ingeskryf het, ons vertrou dat almal iets uit die 4 praatjies kon put. As ek terug dink aan hoe lank Tom gevat het voor hy uiteindelik middagete kon nuttig, was daar definitief stof tot nadenke.

7 P a ge 7 Ons sprekers : V.l.n.r. Tom Robinson, Hoppies Uys, Greg Butler en Prof Karin Jacobs Die BLWK bestuur saam met ons sprekers: V.l.n.r. Pieter Delport, Jacobus Mouton, Hoppies Uys, Tom, Sakkie Rust, Mg Lötter, Johann Strauss, Greg en Karin

8 P a ge 8 BLWK Bestuursvergaderingterugvoer Die afgelope Vrydag het die BLWK bestuur byeengekom om nabetragting van die afgelope konferensie week te hou en ook om te begin beplan vir volgende jaar se aktiwiteite. Ek moet sê dit was n marathon sessie, maar ons glo dat die dinge waaroor daar geredeneer en besluit is, die vereniging vorentoe gaan neem. Die eerste belangrike besluit was oor die datums vir volgende jaar se konferensie. Hou asb Dinsdag 2 Augustus en Woensdag 3 Augustus 2016 oop vir die konferensie. Ons het besluit om slegs een praktiese dag saam met die lesingsdag aan te bied volgende jaar. Daar gaan gepoog word om die praktiese dae vanaf volgende jaar alternatiewelik in die Suid-Kaap en Swartland te hou en sal volgende jaar by die Suid-Kaap begin. Daar gaan nog steeds bruin- en groentoere deur die jaar gehou word, maar slegs een praktiese dag tydens die konferensie. Die idee is om elke jaar n produsent wat lid is van die vereniging te nomineer vir die praktiese dag en sal ons hopelik dan kyk na praktyke op die plaas, maar ook moontlike opstel van proewe waarna gekyk kan word tydens die praktiese besoek. Ons is ook tans besig om twee oorsese sprekers te nader vir volgende jaar se konferensiedag en sal so vinnig as moontlik terugvoer gee oor wie gaan optree. Ons beplan ook om boere te nader om oor hulle bewaringspraktyke te praat en sal sorg dat daar n vertaaldiens is op die konferensie dag, sodat dit nie net tot Engels as voertaal beperk word nie. Ander moontlikhede waarna gekyk word is n inligtingsdag vir Landbouskole en skole waar landbou as vak aangebied word om sodoende ons jeug vroeg al bloot te stel aan die belangrikheid van bewaringslandbou. Daar gaan ook gepoog word om die universiteite waar landbou aangebied word te betrek. So ook is daar n idee om n inligtingsdag vir plaaswerkers op die been te bring om die konsepte van bewaringslandbou ook hier verder uit te bou. Soos julle kan sien is die bestuurspan regtig ywerig om die BLWK uit te bou en ook sodoende meer te kan bydra tot die sukses van bewaringslandbou binne die Wes-Kaap.

9 P a ge 9 CAWC management meeting feedback During the management meeting held on the 25th of September the past conference was discussed and planning for next year was started. It was a long meeting, but the discussion coming out of it will surely take the association forward in the coming year. The first important piece of feedback is the date for next year s conference. Please note the 2nd and 3rd of August 2016 (Tuesday and Wednesday). It was decided that only a single practical day will be held along with the conference day. The practical day will be alternated between the southern Cape and the Swartland each year. Next year the southern Cape will be used. There will still be green and brown tours each year, but only one practical day in the conference week. The idea is to nominate a producer (member) each year on whose farm the practical day will be held. We can then discuss how conservation agriculture is practiced on the farm and possibly do some smaller trials as extra discussions points. We are also currently talking to two presenters from overseas as possible speakers at next year s conference and will keep you up to date with the planning. We will also be making use of local farmers as speakers during next year s conference and will source a proper translation service to ensure that they can talk in Afrikaans if necessary. Other possible ventures that we are looking at are an information day for agricultural schools and schools that teach agriculture as a subject to ensure that the younger generations are introduced to conservation agriculture early, maybe also include the local universities too and also n possible information day for farm workers to help with broadening the understanding of conservation agriculture. I hope it is clear that the management team of the CAWC is really positive and willing to make the effort in extending the contribution of the association to improve conservation agriculture in the Western Cape.

10 P a ge 10 The selfie competition Please remember to take a selfie or have someone take a pic of you with the bumper sticker and post it on our facebook page to be eligible to win the weekend for 2 people. The completion closes at the end of November and the winner will be announced at the end of January following our next management meeting. If you would like to be eligible for the prize and do not have a sticker, contact MG at devlei@whal .co.za or Johann at johannst@elsenburg.com to obtain one. Tell your friends and family too. Remember that the sticker must be attached to the bakkie, harvester or an agricultural implement to be considered and you have to be in the photo too. The prize is a weekend for two, bed and breakfast valued at R2500. Facebook: Our twitter

11 P a ge 11 Moontlike toer na Suid-Australië se CA konferensie Daar was n paar manne wat aangedui het dat hulle belangstel om dalk SANTFA se CA boerdedag in Februarie 2016 te gaan bywoon. Ons het met Tom geskakel en hulle is bereid om vir die wat belangstel, akkommodasie te verskaf en ook n paar besoekpunte te organiseer na die boeredag. As iemand belangstel om te gaan kan julle gesrus met MG Lotter skakel by devlei@whal .co.za, want as daar n groep is wat wil gaan kan mens altyd die vlugbespreking ens. as n groep doen en dalk beter tariewe beding.