CAWC Tour in March. February 2018 Issue/Uitgawe 62. Alle voorspoed vir die jaar.

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1 CAWC Tour in March February 2018 Issue/Uitgawe 62 Newsletter BLWK/CAWC: Your monthly guide Content The influence of cover crop type and management on the weed seedbank under conservation agriculture. Indië Desember Soil health science challenges ancient agriculture concepts Black oat (Avena strigosa) On the Offensive with Cover Crops Photos Upcoming farmers days and events: »» 14 tot 23 Maart 2018: BLWK toer»» 13 Maart: Overberg Agri Voorsaaidag Rietpoel Hallo Almal Januarie is verby en dit is lekker om die eerste nuusbrief van die maand uit te gee. Ons beplan verskeie interessante groen en bruintoere vir die jaar en sal die inliting deurgee met tyd. Eerste op die kalender is die BLWK toer na Rietz se Herlewingslandboukonferensie. Die toergroep bestaan uit 18 lede en ons sal na die toer n lekker insetsel vir nuusbrief doen. Julle kan sommer nou al ook die BLWK konferensiedatums vasmaak. Dit gebeur vanjaar op 7 en 8 Augustus. Ons gaan baie interessante sprekers en onderwerpe aanbied en die praktiese dag, wat vanjaar op Tygerhoek plaasvind, gaan ook poog om relevante besoeke te lewer.»» 14 Maart: SKOG Voorsaaidag Alle voorspoed vir die jaar. Moorreesburg Hi Everybody»» 7 en 8 Augustus 2018: BLWK konferensie week It still amazes me how quickly time flies. January has come and gone»» 22 Augustus 2018: Riversdal and it is great to present the first newsletter of We are planning Boeredag several interesting green and brown tours this year. More details on these will be forthcoming during the year. Our first big event is the CAWC Tour to the Reitz Regenerative Agriculture Conference in March. The tour group consist of 18 people and we will give feedback on the trip in an upcoming newsletter. The CAWC annual conference will take place on the 7th and 8th of August at Elsenburg and Tygerhoek. Interesting talks will be on offer on the 7th, including an international speaker and local farmers. We will also have a talk on the carbon footprint of wheat production in the Western Cape. The practical day will be hosted at Tygerhoek near Riviersonderend. May you have a prosperous 2018.

2 THE INFLUENCE OF COVER CROP TYPE AND MANAGEMENT ON THE WEED SEEDBANK UNDER CONSERVATION AGRICULTURE THE INFLUENCE OF COVER CROP TYPE AND MANAGEMENT ON THE WEED SEEDBANK UNDER CONSERVATION AGRICULTURE Conradie GWDR and Strauss JA Western Cape Department of Agriculture, Private Bag X1, Elsenburg, Introduction Introduction of cover crops to improve soil health can affect the weed seedbank in terms of weed density as well as a possible shift in certain weed species, better adapted to the changed environment. The aim of this study is to determine the weed seedbank dynamics in terms of specie composition and density. Results and discussion The two dominant weed species were Lolium and Conyza. Materials and methods The study is in progress at the Langgewens Research Farm near Moorreesburg, Western Cape. Three methods of cover crop termination within two cover crop mixtures (70%/30% combination), predominantly grass or predominantly legume were evaluated. Termination methods include (1) rolling crop towards end of the growing season and left as mulch, (2) biomass removed as hay and (3) mob grazed by sheep. A composite soil sample were taken in each subplot to a depth of 5 cm at the end of March 2017, placed in trays and irrigated regularly to stimulate germination. Weed seedlings were identified, counted, noted and removed at monthly intervals over a period of 6 months. Conyza seedling numbers were significant (P<0.05) lower in the legume cover compared to the grass cover (Figure 1). Significant interaction was found between cover crop type and different termination method regarding Lolium seedlings.m -2 (Figure 2). Terminating a grass cover crop by making hay resulted in significant more Lolium seedlings.m -2 than grazing it or using a legume cover crop terminating it with any of the three methods. Using a grass cover crop as a mulch did not result in a significant increase in Lolium seedlings.m -2. 2

3 THE INFLUENCE OF COVER CROP TYPE AND MANAGEMENT ON THE WEED SEEDBANK UNDER CONSERVATION AGRICULTURE Conclusions Preliminary results show that type of cover crop may influence the number of weeds germinating during the following season and that the method of termination may also play a role. Management recommendations will only be finalised after completion of the study after at least 3 years of data capturing. Links of the month Click on the button to visit the website. Please note you will need an Internet connection Up to 7 Billion Tonnes of Carbon Dioxide Can Be Removed From the Atmosphere Each Year Through Better Soil Management on Farmland Soil Restoration: 5 Core Principles Plants share information using nature s fungal internet The Global Soil Organic Carbon Map V1.0 Seed Drill Calibration The robots are coming 3

4 Indië Desember 2017 Indië Desember 2017 By Chelsea Harvey, ClimateWire on November 17, 2017 publish in Scientific American Die wêreld is darem maar n groot plek. n Plek vol verskillende kulture, temperature en geure. Ek het die voorreg gehad om Noordoos Indië(Nagaland) te besoek oor Desember Ek het daar gaan stap, maar ook tussen die mense van Nagaland gebly en die geleentheid gehad om n totaal ander boerdery gemeenskap te sien en te beleef. Indië gee n totale ander perspektief oor die term ekonomie van skaal. Indië is onder die wêreld se top drie produserende lande van verskeie voedsel soorte bv: Rys, Melk en Koring. Dit is die land met die grootste buffel en bees getalle ter wêreld en is ook die grootste melk produsent. Naas Amerika het Indië die tweede grootste bewerkbare landbou hektare en die grootste besproeiings hektare. Dit is indrukwekkend, veral wanneer jy besef 70% van plase in Indië is 1-2 hektaar groot en die gemiddelde melk kudde is 1 tot 2 koeie. insetkostes. Wat ek wel by hulle geleer en ervaar het is die volgende: n Trots, op wat hulle doen en wie hulle is. Al is dit eenvoudig is hulle tog trots. n Merkwaardige prestasie vir wat ons as bestaansboere definieer. Ek het die voorreg gehad om so 30 jongboere in Manipur toe te spreek en oor bewaringslandbou beginsels te kon gesels. Hulle het dit baie waardeer en besef dat bewarings beginsels van belang is om volhoubaar voort te boer. n Wonderlike leerskool, waar ek weereens besef het dat hulle dieselfde uitdagings as ons het in terme van markte en 4

5 Indië Desember 2017 Hulle produseer wat die mark nodig het of wat gaan verkoop. Hulle het n baie sterk gemeenskaps uitkyk en gewilligheid om goed saam te doen en mekaar te help. Hulle boer as gemeenskap saam teen die hange van die suidelike Himalaja berge. Met lappies lande wat uit die berge se klowe natgelei word. Alles met die hand. Dit was n ongelooflik ervaring en het my uitkyk oor landbou en die lewe verryk. Ek sluit af met n gesegde wat ek onlangs gelees het. Our job as farmers is not to feed the world, despite what the yield is king lobby might tell you. Our job is to feed our families, make a profit and produce food people want to eat. John Cherry Mag dit jou boerdery uitkyk vernuwe Voorspoed en groete Hoppies Uys 5

6 2018 REGENERATIVE AGRICULTURE TOUR TO MID-WEST, USA AUGUST th to 18 th August 2018 We fly to Bismarck, ND where we visit with Gabe Brown at his ranch as well as Menoken Farms. We travel through North Dakota, South Dakota, Nebraska, Iowa, Missouri and Kansas. You will visit some of the most impressive regenerative farming operations in the Mid-West, USA. The tour ends with a one-day comprehensive Soil health workshop with prominent US Speakers on this topic. All-inclusive cost is US $ 5700 per person and limited to 12 people. All-inclusive cost is US $ 5700 per person. This tour is limited to 12 people only. To book your seat call Tour Highlights Willie Pretorius on or mail to willie@soilhealthsolutions.com 6

7 Tour highlights Visits to the Browns ranch for a full day with Gabe s undivided attention Menoken farms with Jay Fuhrer, the Keynote Speaker at our Reitz & Cape 2018 Regenerative Agriculture Conferences Dakota Lakes Research farm with Dr Dwayne Beck Blue Dasher farms with Dr Jonathan Lundgren Chris Teachout will demonstrate some very interesting intercropping combinations on his farm in Iowa Darin Williams in Kansas: Demonstrating zero input cropping techniques using non-gmo seed and doubling County yield averages on Soya beans and other crops Gail Fuller, a leading Regenerative Agriculture farmer in Kansas, will demonstrate how he mimics nature on his farm. Visit to Ward labs and Green Cover Seed facility and their research plots as well as several other facilities A barbeque with a typical Midwest American family The tour ends with a full day workshop with Dr David Johnson from New Mexico State University as the Keynote Speaker BOOKING AND OTHER ARRANGEMENTS Confirmation will be on a strictly first come basis and we can, for practical purposes, only accommodate 12 participants. We would require a 50 percent deposit (payment in SA Rand based on the rate of exchange on the date of confirmation). The balance to be settled by end June 2018 The closing date for registration will be end of March 2018 or earlier if fully subscribed. The costs cover all travelling and hotel expenses, tour leader, workshop and other venue costs. Hotel costs include breakfast, but evening and other meals are excluded and are for your own account. Hotel accommodation is for single rooms per person at hotels with no less than a 3-star grading. Should you want to extend your stay after the tour this could be arranged. We will not be responsible for entry visas into the USA but will furnish a letter confirming your participation on the tour. Personal accident and medical emergency travel insurance must be obtained by each participant as we will not be held responsible for any claims in the unlikely event of an accident or any other mishap. There will be a 20% cancellation fee if tour participation is cancelled after 1st of May Each participant will be required to sign an indemnity for any claims against the tour organizers. 7

8 Soil health science challenges ancient agriculture concepts Soil health science challenges ancient agriculture concepts DICKINSON, N.D. It s a tall order to clear any misconception particularly one that s 7,000 years old. Yet that is precisely what Jon Stika and researchers at the North Dakota State University s Dickinson Research Extension Center have been doing for many years now as they make new discoveries and introduce new paradigms to the world of soil health. I started talking about soil health in 1992 and that s when this awareness sort of really started, Stika said. We could classify soils by type, by their characteristics, and we can measure all the chemical properties... but no one was really asking how well is this soil functioning? The answer to that question requires a fundamental shift in how soil is seen. It s taken years of research and a lot of evidence to demonstrate to skeptics that soil is not merely dirt, but a living organism a system of living organisms unto itself. It s been (seen as) this give-and-take, (that) the soil is a bucket you put things into and take things out of, Stika said. Now we re realizing that no, soil is a biological system. It can provide everything these plants can need. Soil is an agri-biome which refers to an interdependent environment of organisms serving a greater whole. An example Stika gave is the human biome which is the description given to all of the microbial organisms that live within and upon human beings. Close to half the living cells in a human body, by number, Stika said, aren t actually human. Another example he gave is how bovines need the microbes within their rumen in order to properly digest grass. They re realizing that there s a number of human diseases that they re looking at right now that may be very closely linked to what sort of organisms are living in your digestive tract. So the cure for some of these diseases may be... you don t have the right biology living in your digestive system, Stika said. We re looking at the same thing with the soil. For about 7,000 years human beings have been tilling the soil, inadvertently destroying the very resource they sought to utilize, Stika said. The soil s complex biological relationships are damaged by practices like tilling. Likening it to a human house, Stika said that tilling the earth destroys that house, and leaves a cold and weakened soil system in its place. 8

9 Soil Aggregates Found in Great Soil Just Like Christmas (Soil health practices are) basically restoring everything that was there before we messed with it. This is all the biology that s supposed to be there, that s supposed to be working with these plants, Stika said. If you can restore it all and it can all function the way it was supposed to function...what s the limit? So far, it s been impressive. An example of soil health practices being successfully applied can be found in ten acres of certified organic soil that the center has been using to grow crops and test a few different soil health inputs. One of those has been inseminating the soil with mycorrhizal fungi, a type of fungus that attaches to a plant s roots, feeding off the plant s nutrients while providing access to nutrients in return. They go out into the soil, they can go into smaller spaces in the soil than the plant root can. They can get water, phosphorus, whatever and they give it back to the plant and the plant can give them food, Stika said. This year we saw it with our drought... we still had average yields on everything that was grown there. (Mycorrhizal fungi) is just one organism that works with these plants to acquire what they need. Soil health demonstration projects have produced some very dramatic results an eight year study of soil health on plots located just south of Manning, N.D., saw a dramatic increase in water infiltration after that time, meaning the soil absorbed more of the rainwater it received. NDSU is so confident in the practical applications of soil health that it boasts a fifty-pound nitrogen credit for producers who practice no-till for five year spans. So far, NDSU has been able to say... if you don t till your soil for at least five years, you can give yourself a fifty pound credit, so when you get a soil test back and it says you need 100 pounds of nitrogen, you only need fifty, Stika said. NDSU as a whole has a vision of looking at this agri-biome more, so there s going to be more of that coming. Stika said that the average western North Dakota farm runs about 1,500 to 2,000 acres in size, and fifty pounds per acre of nitrogen comes to about $20, which results in a not insignificant amount of savings, and that s just over five years. Stika anecdotally revealed that he s been practicing notill in his personal garden for 15 years now. Recently he sought to plant some sweet corn, and after he sent his soil off to get tested, the results came back and told him he didn t need to add any additional fertilizer. How can we grow crops and livestock profitably and restore soil health all at the same time? It s very doable, Stika said. In some ways, as you restore soil health and the soil becomes more efficient at what it can do, you become more profitable. 9

10 Tweede jaarlikse grondgesondheidsdag (met die samewerking van Landbouweekblad) Verbeter jou plaas se inkomste deur die beginsels van bewaringslandbou toe te pas Donderdag 22 Maart 2018 Venue: Morgensrust, Owl-straat 60, Joostenbergvlakte, Wes-Kaap LAAT DIE NATUUR VIR JOU GELD MAAK Herlewingslandbou is boere se kostedoeltreffende wapen teen stygende insetkoste en klimaatsverandering, deur natuurlike prosesse weer optimaal te laat funksioneer. Landbouweekblad met die samewerking van die Soil Health Support Centre en Nu-Way, n filiaal van Nulandis bring wêreldbekende sprekers, kenners en puik boere byeen om oor herlewingslandbou te praat, om só hoop te bring vir duisende boere wat in n onverbiddelike kosteknyptang vasgevang is. Program Die hoofspreker is die Amerikaner Jay Fuhrer, n wêreldbekende kenner van herlewingslandbou, wat praat oor die gebruik van dekgewasse en die integrasie van vee om grondgesondheid tot op die hoogste vlak te voer. Johann Zietsman, wat al wêreldwyd gekonsulteer het oor weiding, gaan wys hoe jy jou plaas se drakrag kan verdriedubbel en jou grond kan opbou. Willie Pretorius, n grondgesondheidskundige, en Sheila Storey, een van Suid-Afrika se bekendste nematoloë, wat by die vestiging van die Soil Health Support Centre betrokke was, gaan n oorsig gee oor die gratis voedingstowwe en ander hulpmiddels wat in die natuur voorkom, en watter praktyke toegepas kan word om dit doeltreffend in gewasproduksie te gebruik. Rens Smit, n meestersgraadstudent aan die Universiteit Stellenbosch, wat puik werk doen met dekgewaskombinasies, gaan sy resultate bespreek. Hendrik Pohl van ZZ2 se vrugteplaas op Ceres gaan inligting gee oor die uiters indrukwekkende werk wat hulle met appels doen. Lourens van Eeden, n bewaringsboer van Swellendam, gaan sy indrukke gee van n onlangse toer deur die Amerikaanse Midde-Weste, asook die lesse wat hy geleer het en wat hy op sy eie boerdery kan toepas. Dr. Johann Strauss gaan praat oor hoe bewaringslandbou deur die klimaat beïnvloed word. Koste R1 100 per persoon en R550 vir studente (toon n geldige studentekaart). (BTW ingesluit.) Koffie, tee en middagete is ingesluit. Navrae en besprekings Dalene Ricketts E-pos: DRicketts@Landbou.com (skryf Kaapse konferensie in die onderwerpveld); tel

11 Second Annual Soil Health Day (in collaboration with Landbouweekblad) Improving the farm income bottom-line with regenerative agricultural principles 22 March 2018 Venue: Morgensrust, 60 Owl Street, Joostenbergvlakte TIME TOPIC SPEAKER 07:00 07:45 Registration and coffee 08:00 08:10 Devotional opening Ds Erika Ras NHK, Bellville 08:10 08:20 Opening address Main sponsor 08:20 08:30 Introduction 08:30 09:30 09:30 09:40 Q & A 09:45 10:15 Key note address Regenerative agriculture as the farming solution Impact of conservation agriculture under challenging climatic conditions 10:20 11:00 Are free resources being used effectively on our farms? 11:00 11:20 COFFEE / TEA 11:30 12:15 The benefits of biological principles on a fruit farm 12:20 12:45 Using nematodes as indicators for soil health 12:50 13:15 Cover crop utilization in a Mediterranean climate nutrient dynamics and performance of wheat Chris Burgess Editor of Landbouweekblad Jay Fuhrer Soil Health specialist, NRCS Bismarck, ND, US Dr Johann Strauss Scientist: Sustainable cropping systems; Directorate Plant Sciences Elsenburg Willie Pretorius Soil Health Solutions & Soil Health Support Centre Hendrik Pohl Operations manager, ZZ2 Fruit Farm, Ceres Sheila Storey Nemlab & Soil Health Support Centre Rens Smit M.Sc. (Agric) student, Stellenbosch University 13:15 14:00 LUNCH 14:05 14:40 Lessons from a recent American tour Lourens van Eeden of regenerative farms in the Midwest Grain farmer, Swellendam 14:45 15:30 Soil health and ultra-high density grazing Johann Zietsman 15:30 16:00 Panel discussion; closing remarks 16:00 16:30 COFFEE / TEA 11

12 Black oat (Avena strigosa) Black oat (Avena strigosa) Common names Black oat, lopsided oat, bristle oat, sand oat, small oat [English]; avoine maigre, avoine rude [French]; aveia preta, aveia-estrigosa [Portuguese]; Rauhhafer, schwarzhafer [German]; ukonkaura [Finnish]; busthavre [Norwegian]; purrhavre [Danish, Swedish] Species Avena strigosa Schreb. [Poaceae] Feed categories * Forage plants * Cereal and grass forages Related feed(s) * Red oat (Avena sativa) forage * Oat forage Description Black oat (Avena strigosa Schreb.) is an annual grass from temperate areas that is used mostly in South America for forage for its good nutritive value and productivity. The following video (in Portuguese) presents black oat in Brazil and its favourable characteristics (Chini, 2014): Morphology Black oat is a tufted grass with an upright habit. It can grow to a height of m, depending on growing conditions. It has a dense root system. Black oat is a leafy species. The leaf blades are linear, flat, rough and numerous. The inflorescence is a loose open panicle. The panicle is drooping and bears pendulous, pedicellated spikelets. The inferior lemma is awned, straight and black (hence the name black oat), cm long, somewhat lopsided (hence the name lopsided oat). The fruit is a hairy caryopsis. Avena strigosa has morphological differences from the common oat (Avena sativa): it is leafier with side panicles (instead of equilateral), plump kernels (instead of narrow), and smaller seeds (Diederichsen, 2014a; Husson et al., 2012). Though black oat is the common name of Avena strigosa in English and other languages (aveiapreta in Portuguese), it should be noted that some varieties of Avena sativa also produce black grain, notably in France where black varieties of Avena sativa are very popular and more common than white ones (Sem-Partners, 2014). 12

13 Black oat (Avena strigosa) Utilisation Black oat is a valuable forage crop. It has earlier growth and a shorter production cycle than ryegrass, a high DM productivity and a high nutritive value with a good protein content (Dial, 2014; Paris et al., 2012; Macari et al., 2006; Sobczak et al., 2005). Black oat is a valuable cover crop used both in summer and winter (Dial, 2014; Brust et al., 2012; Suttie et al., 2004). Black oat can be grown for forage only or for forage and grain (Fontaneli et al., 2012). Its dense root system is beneficial to soil texture (Husson et al., 2012). Black oat used to be cultivated in northern Scotland as human food (grain), and for animal feeding as pasture, hay or grain (Weibull et al., 2002), but is now cultivated mostly in South America (Diederichsen, 2014b). Black oat can be grown on waste water from which it removes nutrients and thus reduces organic load. It is also reported to extract Cd (heavy metal) from the soil (Eustaquio Junior et al., 2010; Uraguchi et al., 2006). Black oat is a diploid Avena species that has great potential for the maintenance of biodiversity among oats and for breeding programmes (Husson et al., 2012). Distribution Black oat is native to the Iberian Peninsula (Spain and Portugal). It was cultivated in marginal environments or was a tolerated weed in cultivated oats (Avena sativa L.) in many parts of Europe (Mordvinkina, 1936 cited by Diederichsen, 2014a). Black oat almost completely disappeared from cultivation in Europe but there are relicts in the Scottish Islands and Lithuania (Diederichsen, 2014a). Most black oat is now cultivated in South America. The total global area of harvested lopisded oat was about 5 million ha in 2008, with 3 million ha in Brazil (Diederichsen, 2014b). It is also cultivated in temperate areas of Argentina, Uruguay and Chile, and in the tropical high altitude areas of Bolivia, Ecuador and Peru as a winter cover crop. In North Vietnam, black oat has been assessed for its ability to provide fodder during cooler periods (Salgado et al., 2010). In the south-eastern United States, Hawaii and Arizona, black oat is used for forage pasture and as a cover crop (Dial, 2014). Black oat is a fast-growing forage that can be harvested 6 weeks after sowing (Gold Steinberg et al., 2005). It can grow from sea level up to an altitude of 1000 m (Fontaneli et al., 2012). It does well in places where summer temperatures remain cool (Suttie et al., 2004). Some Brazilian cultivars are adapted to more tropical conditions (good grain filling under high temperatures), while others are one of the most important winter cover crop in southern areas of Brazil where winter climatic conditions limit the growth of tropical forages (Rio Grande do Sul, Parana) (Silva et al., 2006). With Italian ryegrass (Lolium multiflorum), black oat is the most utilized temperate species in the cool season (Sobczak et al., 2005). Black oat does not survive below -8 C. It is tolerant of drought. It can grow on relatively infertile soils provided they are sufficiently drained (sandy or loamy soils, heavy clay with low nutrient value) (Fontaneli et al., 2012). Some cultivars have a high tolerance to Al in the soil (Crestani et al., 2009). Black oat prefers full sunlight but can grow in association with forage legumes. It has an outstanding resistance to rust (Puccinia graminis) (Gold Steinberg et al., 2005). Forage management Establishment and associations Black oat can be sown alone or in combination with grasses such as Italian ryegrass (Lolium multiflorum) and elephant grass (Pennisetum purpureum), or legumes such as berseem (Trifolium alexandrinum), stylo (Stylosanthes spp.), pinto peanut (Arachis pintoi) or vetch (Lathyrus or Vicia spp.) (Paris et al., 2012; Uhlein et al., 2008). In Brazil, Avena strigosa is generally cultivated in pure stands or associated with Italian ryegrass or legumes, and used as pasture. Black oat and elephant grass can be associated in a pasture because growth of the black oat is higher in the winter period whereas elephant grass grows more in summer (Sobczak et al., 2005). Yield Black oat yields about 3-8 t DM/ha (Salgado et al., 2013; Salgado et al., 2010; Cabral et al., 2010; Eustaquio Junior et al., 2010; Suttie et al., 2004). Pasture and cut-and-carry Black oat can be grazed or cut and then chopped and stall-fed (fresh) (Salgado et al., 2013). Moderate grazing should be done to improve forage production and animal performance. Black oat can be grazed rotationally during short periods (1-3 days) by high producing animals, which are then kept out for 30 days before re-entering the sward. Under such a system, black oat should not be grazed or cut below 7 cm in height. Under continuous grazing, stocking rate should be adapted to plant 13

14 Soil health science challenges ancient agriculture concepts growth so that the stubble is comprised between 20 and 40 cm (Fontaneli et al., 2012). Hay and silage Black oat may be cut at the vegetative stage and dried to make hay or silage. Prior wilting is recommended for silage production due to its high moisture content, low soluble carbohydrates and high buffering power that prevents a reduction in ph. The use of bacteria such as Lactobacillus acidophilus and/or enzymes may improve silage quality (Berto et al., 1997). Environmental impact Cover crop Black oat is a valuable winter cover crop in places where frost does not occur. It tillers readily, providing good soil coverage. Black oat produces more mineral N than other cover crops such as rye (Schomberg et al., 2005). Black oat has a good C:N ratio that is favourable for soil N management (Dial, 2014). Black oat is efficient at translocating soil phosphorus in oxisol soils (Antony, 2007). In the northern part of Parana (Brazil), planting black oat as a winter cover crop resulted in increased soybean yield (+ 38%) and increased bean yield (+ 68%) (Derpsch et al., 1985 cited by Machado, 2000). Weed control Black oat prevents the development of broadleaf weeds. In the USA, it controlled 34% of weeds while other cover crops, such as rye, only controlled 26%, and wheat 19% in cotton grown under conservation tillage (USDA, 2005). Though it has been reported as having some allelopathic effects on cottonseed, the use of black oat as a cover crop had a better residual effect than rye on a following cottonseed crop (Bauer et al., 1999). Nematode control Black oat is reported to have nematicidal effect. As a cover crop, black oat was shown to be resistant to or inhibit root-knot nematodes (Lima et al., 2009). The use of black oat as a fallow crop before strawberry cultivation reduced nematode lesions more efficiently than sorghum (Sudan grass) or common oats (Dial, 2014). Some breeding programmes aim at selecting nematode suppressing black oats (Diederichsen, 2014a). Phytoremediation In Japan, black oat was reported to have good potential for cadmium extraction from agricultural soils (Uraguchi et al., 2006). 14

15 On the Offensive with Cover Crops On the Offensive with Cover Crops In the past few years, we have made a concerted effort to increase the usage of cover crops and other conservation practices on our farm. I have learned a lot of lessons from this experience but one stands out above the rest. Being a good steward of the environment and aiming to produce high yields don t have to be mutually exclusive. In fact, I would argue that if intensively managed, conservation practices should significantly enhance yields. the critical nutrients or soil conditions is deficient, plant growth will be limited even if all other critical nutrients and soil conditions are abundant. It can be best visualized by looking at a picture of a barrel with staves of different lengths. Despite other stave heights being full, you can t fill the barrel with water any higher than the most limiting stave. The cornerstone of any good crop production system involving conservation techniques is the establishment of cover crops. Cover crops have traditionally been thought of as a defensive measure... a way to protect crop yields during dry spells, a way to protect soil from erosion and a way to shade out competing weeds like palmer amaranth. But while the defensive qualities of cover crops are certainly great, what excites me the most about cover crops is actually their ability to enhance crop yields, especially in years where weather conditions are already favorable. Cover crops ability to take a good crop yield and make it great can be explained by considering the framework of something known as Liebig s Law of Minimum, which can be summarized as If one of 15

16 On the Offensive with Cover Crops So what does this have to do with cover crops? As mentioned above, in years where water is your limiting factor cover crops can help mitigate some of the water stress by increasing the soil s water holding capacity and also by providing shade to the soil surface. Here are some interesting facts regarding soil temperature courtesy of NRCS: At 70 degrees soil temperature, 100 percent of the soil moisture is used for plant growth. At 86 degrees, soil microbial activity begins to decline. From 95 to 113 degrees, 15 percent of soil moisture is used for plant growth and 85 percent for evapotranspiration. How often do our soils approach the critical temperature state during the hot summer months in SC? The presence of a thick stand of cover crops can help ensure that soil moisture isn t the limiting factor to your field crops. If soil moisture isn t that limiting factor, then how do you ensure that nutrients are abundant enough and don t become that limiting factor themselves? One option is to fertilize to the highest yield potential of the crop, but the obvious issues with doing that are excessive cost and nutrient runoff/leaching. Once again, cover crops can play a role in helping our crops reach their highest potential yield. Cover crops help row crops access additional nutrients in the soil profile through four different biological processes: 1) The breakdown of carbon from decaying cover crop residue, 2) Roots from the cover crops produce exudate acids which convert minerals in the soil into plant available nutrients 3) The cover crops act as a host plant for arbuscular mycorrhizal fungi, which are microbes that have a direct effect on plant health and nutrient storage capacity of the soil within the root zone of the plant and 4) By producing additional Nitrogen with leguminous cover crops. While I do not believe the cover crops are a complete substitute for traditional fertilizer programs, I do believe that they are a great compliment and can serve to enhance the nutrient bank available to your crops. They can raise the bar on what the limiting factors affecting your crop are within a given year. 16

17 So if you re interested in incorporating cover crops into your row cropping system, here are some tips that I ve learned through both good and bad experiences on our farm. Treat cover crops like a cash crop when it comes to timing. Timely planting allows a longer growing season and generally, a longer growing season for the cover crops equates to a larger economic benefit. Our most impactful cover crops have been those following corn for this reason alone. Along the same lines, timely termination of the cover crop can prevent a lot of headaches come planting time. Utilize multi-species mixes to get the best synergies of biological interactions. For example, brassicas can suppress nematodes, legumes produce nitrogen and small grains are good mycorrhizal hosts. To find a good seeding rate, take the normal planting rate used for each seed type and divide it by the number of species within your mix. Limit your costs by saving seed to re-blend, especially small grains, but don t skimp on seeding rate. The best case scenario is to balance out your blend amongst each species but if costs are prohibitive it s better to increase the rate of small grains than to just use a lower overall rate. Try to plan in advance your crop rotations so that your cover crops complement your cash crops and don t inadvertently suppress them. For example, you do not want to plant legumes immediately prior to or behind a leguminous cash crop such as peanuts and soybeans because it could lead to disease issues. On the Offensive with Cover Crops Make it a goal to have a living root in the soil for 95% of the year. If you can do that, the biological activity mentioned above never stops and your crops are the beneficiaries. Getting good seed-to-soil contact can be a challenge when planting into thick cover, but the cover crop s root fibers can help prevent soil crusting so don t be afraid to plant slightly deeper than normal. Lastly, have a long-term perspective. While cover crops can certainly have an economic benefit in the short term, it s the biological activity over the long-term that really improves your soil and yields. This is especially true here in our sandy, low CEC soils. Adding multi-species cover crops to our farm has been a fun learning experience and has improved our soil quality and yields. There is still so much to learn and I m sure our practices will evolve with experience and increased knowledge. If you are interested in giving multi-species cover crops a try, I d encourage you to stop by the NRCS office in Bennettsville and speak with Frank Stephens about potential conservation programs that can help you get started. Remember, if you take care of the land, the land will take care of you. 17

18 Photos BLWK Bestuurspan / CAWC Management Team Lede Hoppies Uys hoppies@swdconnect.co.za / hoppies@easycoms.co.za Sakkie Rust sakkie@rautenbachtransport.co.za MG Lötter devlei@whal .co.za Pieter-Jan Delport jpdelport@overnet.co.za Jakobus Mouton andre@patat.za.net Amelia Genis agenis@landbou.com Johann Strauss johannst@elsenburg.com Pieter Blom (SSK) pblom@ssk.co.za Ruan Schutte (Overberg Agri) - rschutte@overbergagri.co.za Wynand Heunis (Overberg Agri) - WynandH@overbergagri.co.za Pieter Burger (Kaap Agri) pieter.burger2@kaapagri.co.za Lombard van Jaarsveld lombardvj@overbergagri.co.za Peter Greeff peter@orchman.com Click on the address to send a person an 18