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1 05/02/2014 ISSUE 22 UITGAWE 22 NUUSBRIEF / NEWSLETTER Inside this issue: Inhoud: Bruin toer / Brown tour Announcement / Aankondiging Nuus/News Carbon footprint 5 Hallo Almal CA and manure 7 Carbon accumulation Website 13 9 Die eerste maand van die jaar is verby en binnekort begin die verskeie Voorsaai-boeredae weer. Die Suid-Kaap het goeie reën deur die somer gehad en selfs die Swartland lyk plek plek groen (maar miskien is dit maar nog onkruid wat gespuit moet word). Op Tygerhoek naby Riviersonderend het daar selfs al medics opgekom. Our first Brown tour for the year is scheduled for the 12th of March and we hope to see you all there. Details can be seen on pages 2 and 3. Member fees and 14 Gedurende die afgelope gesamentlike kongres van die vakverenigings van gewasproduksie, onkruidwetenskap, grondkunde en hortologie het die bewaringslandbouproewe van die Wes-Kaapse Departement van Landbou 3 pryse opgelewer. Een beampte en twee studente het pryse gewen, terwyl nog twee studente van die fakulteite Grondkunde en Agronomie ook pryse gewen het. Die Wes-Kaap se navorsing staan sterk. Upcoming farmers days and events: Overberg Agri Voorsaaidag 27 Februarie 2014, Rietpoel SKOG Voorsaaidag 19 Maart 2014, Moorreesburg Hope that you enjoy the new newsletter. Please feel free to send me articles or interesting snippets that we can share with all our readers. Groete van huis tot huis Johann Strauss

2 P a ge 2 BEWARINGSLANDBOU DIE BRUIN TOER OVERBERG Woensdag, 12 Maart 2014 Die Vereniging van Bewaringslandbou Wes_Kaap (BLWK) nooi u graag uit na ons Bruin Toer by Caledon. Die Bruin Toer is n somer byeenkoms waar navorsers en kundiges gekry word om praktiese besprekings met produsente te geniet en idees te wissel in verband met bewaringsboerdery. Hierdie geleentheid bied produsente die kans om met kundiges probleme en oplossings oor hedendaagse landbou omstandighede te bespreek en selfs onderwerpe vir nuwe navorsing te identifiseer. Inligting Plek: De Vlei Plaas, op R43, 2km vanaf N2 na Villiersdorp op linkerhand GPS: , (kaart aangeheg) DATUM EN TYD Woensdag, 12 Maart 2014 Tyd: 08h30 vir 09h00 Verversings sal voorsien word. RSVP: Woensdag, 5 Maart 2014 by MG, sien kontakbesonderhede op volgende bladsy ONDERWERPE Die dag begin met drie voorleggings en vandaar word daar na verskeie landpersele met grondprofiele beweeg vir praktiese samespreking. Proses van Bewaringsboerdery Dr. Johann Strauss Parameters vir grondkwaliteit en stikstofnorme vir Bewaringsboerdery Dr. Johan Labuschagne Grondkoolstofstudies Jacques Smith Gesonde grondbestuur Profielgate Peter Greeff Demonstrasie en samespreking

3 P a ge 3 Ons sien uit om u by die geleentheid te sien en vra dat u asb voor die RSVP datum vir my in kennis sal stel van u bywoning. Vriendelike groete, MG Lötter devlei@whal .co.za KAART Plek: De Vlei Plaas, op R43, 2km vanaf die N2 na Villiersdorp op linkerhand GPS: , ( DE VLEI

4 P a ge 4 Bewaringslandbou Wes-Kaap Konferensie 2013 Video materiaal nou beskikbaar Dit is lekker om uiteindelik die video materiaal wat in 2013 tydens die konferensie week opgeneem is, te kan vrystel. Jammer dat dit solank geneem het. Die praktiese besoeke en volledige konferensie dag is op n 32GB Flash drive beskikbaar. Die alternatief sou n stel van 11 DVD s gewees het, maar die Koste om dit so te doen was gelykstaande aan die van n flash drive. Die materiaal kos R250. Ons maak geen profit op die materiaal nie. Belangstellendes kan vir my n e-pos stuur by johannst@elsenburg.com. Ons sal dan n faktuur uitreik vir die betaling. Sodra die betaling ontvang is, asook n bewys van betaling, pos ons die materiaal aan u. Meld asb net in die e-pos aan wie die faktuur uitgemaak moet word, asook die pos adres waarheen die materiaal gestuur moet word. Conservation Agriculture Western Cape Conference 2013 Video materiaal now available It is really a happy occasion to introduce to you the video material taken during the 2013 conference week. Sorry it took such a long time. The practical visits' and the full conference day has been put on a 32GB flash drive. The alternative would have been DVD s, but the cost of writing the 11 DVD s was on par with the cost of the flash drive. The cost of the material is R250. No profit is made on the drive. If you would like to order the material send me an to johannst@elsenburg.com. We will then send you an invoice for the drive. As soon as payment has been made and a copy of the proof of payment reaches us, the drive will be sent to you. Please make sure to include in the to whom the invoice must be made out to, as well as the postal address.

5 P a ge 5 Carbon footprint of crop production due to shift from conventional to Conservation Agriculture Laik R1, Saharawat Y1, Singh SS 2, Ladha JK1 1 IRRI-India Office, New Delhi, India; r.laik@cgiar.org 2ICAR-RCER, Patna, India Introduction Acute shortage of conventional energy sources has led to increasing dependence on non-conventional sources. But the safety concern of nuclear power plants which is thought to be main alternative source of energy, especially after tsunami and earthquakes in Japan during early 2011 which caused great damage to power plants. In developing country like India where 67% of the population depends on agriculture,, contributing 28 % of GDP it becomes necessary to think about either saving conventional sources of energy or producing energy by non- conventional means with highest safety standards. Agriculture in developing countries is already under pressure from growing populations, industrialisation and environmental degradation. Climate change is expected to exacerbate and add to these problems. There is also a need for diversification and intensification of cropping system with lower energy consumption when per capita availability of land is decreasing. Energy used on farms can be categorised as direct and indirect energy. The energy which is directly required for various farm operations can be termed as direct where as indirect energy is required for production of different farm inputs, such as commercial fertilizers, pesticides, herbicides etc. The amount and type of energy used in agricultural operations affect overall CO2 emissions and generally CO2 levels increase with higher energy use. CO2 emitted either directly from soil as soil respiration or indirectly due fuel or electricity consumption can be curtailed by changing agronomy, nutrient management, tillage/residue management, water management etc. Improved agronomic practices increase yields and generate inputs of carbon residue and can therefore increase soil carbon storage (Follett, 2001). Reports of minimum or no till effects on soil carbon are mixed (West and Post, 2002; Ogle et al., 2005; Gregorich et al., 2005), but conservation agriculture practices of zero or minimum tillage, crop residue retention and cropping system management as key components can conserve energy in crop production. There is a need to estimate the change in energy requirement for crop production due to shift from conventional to conservation agriculture. Since cereal based cropping systems are the most popular in India an experiment has been planned with different cropping systems in old alluvium non-calcareous non-saline soil of Patna, India, under Cereal System Initiatives for South Asia project.

6 P a ge 6 To estimate the amount of direct energy needed for crop production the carbon footprint principle has been applied. Carbon footprint is the sum of all emissions of carbon dioxide which were induced by activities in a given time frame. It is the best way to calculate carbon dioxide emissions based on fuel consumption. Large plots, each of 1900 m2 have been used in a trial to assess four cropping scenarios with three replications at Sabajpura research farm of Indian Council of Agricultural Research-Regional Council of Eastern Region, Patna (India). Each scenario is a combination of cropping system, crop residue management and tillage operation. Scenario 1 (S1) is the conventional practice followed by most farmers in this region. A small group of farmers now practices recently developed agricultural technology which include zero tillage in wheat (November April) and puddled transplanted rice during rainy season (June November). They also take green gram as cover crop during summer season. This is a system that has been practised for scenario 2 (S2). Conservation agriculture practices are used in scenario 3 (S3), where in addition to zero tillage rice and wheat, zero tillage cowpea is grown as a summer legume crop. To meet the growing demand of food diversification and intensification of cropping system a 4th scenario (S4) has also been examined. This has direct seeded rice in the rainy season, potato and maize in winter and cowpea as relay cropping in summer. Direct use of energy in crop production mainly consists of energy required in tillage and irrigation. When there is a shift from conventional to other agricultural practices there may be a change in energy requirement for crop production. Hence energy consumed in tillage and irrigation was estimated in the four scenarios during rainy and winter seasons. The efficiency of crop production lies in putting less fossil fuel energy into production for a given level of output. Results and Discussion During winter , equivalent CO2 emission due to tillage operation was highest in S1 which was 400% more than that of minimum equivalent emission plot of S3. S4 had significantly more emission than S1 due to mixed cropping of potato and maize. For irrigation it was 20% more emission than S3. In this case also S4 had highest energy requirement. Wheat yield of S3 was 43% more than S1 where as wheat equivalent yield of S4 was 351% more than of S1. In rice it was found that equivalent CO2 evolution from diesel consumption for tillage operation in S1 and S2 were at par. Similarly it was at par in S3 and S4. But zero tillage direct seeded rice in S3 and S4 could save 525 and 348% equivalent kg CO2 ha-1 respectively as compared to conventional tillage rice in S1 and S2. Puddled rice in S1 emitted highest equivalent kg CO2 ha-1 for irrigation by electricity which was19 % more than in zero tillage direct seeded rice of S3. S4 had the lowest emission, perhaps due to greater recycling of crop residues. Irrigation water required in S1 and S2 were at par. Highest rice grain yield was found in S4 which was 30% higher than S1.

7 P a ge 7 Effects of Conservation Agriculture and manure application on maize grain yield and soil organic carbon: a comparative analysis Rusinamhodzi L1, et al; Keywords: continuous maize cropping, degraded soil, animal feed, mulch cover, tradeoffs In southern Africa, most farming systems exhibit a close integration of crop and livestock components, with an output of one component being an input of the other. The allocation of crop residues for livestock feed meets two out of three critical objectives; it ensures feed during the dry season (De Leeuw, 1996), improves quantity and quality of manure to restore soil fertility (Murwira et al., 1995) but does not ensure permanent soil cover required under conservation agriculture (CA). Thus under CA, there are strong trade-offs for either allocating crop residues for livestock feed or using the crop residues directly for mulch thereby reducing the amount and quality of manure available and compromising the condition of livestock. The objective of this study is to perform a comparative analysis of maize grain yield and soil organic carbon (SOC) changes in CA systems versus conventional tillage systems with manure application. Crop residue retention and reduced tillage are options that are expected to increase SOC in the long-term, in a similar way to manure application. Therefore, it is necessary to perform a comparative analysis to quantify the differences and to identify the most sustainable system. Crop yield is important for ensuring food security and income, and SOC is an important determinant of soil fertility, productivity and sustainability (Lal, 1997). Data were obtained from two sets of long-term experiments under continuous sole maize (Zea mays L.). The experiment on manure application was established in 2002 until 2010 on both clay (Chromic Luvisols) and sandy (Haplic Lixisols) soils (FAO, 2006), and two field types (homefield and outfield) in Murehwa, Zimbabwe. The treatments included a control, 100 kg N ha-1, 100 kg N ha t manure ha-1 and 100 kg N ha t manure ha-1. The tillage experiment was established in 1988 to 1999 at three sites, Domboshawa (sandy soils, Haplic Lixisols), Makoholi (sandy soils, Ferralic Arenosols) and Institute of Agricultural Engineering (IAE) (red clay soils, Chromic Luvisols) (FAO, 2006). Conventional mouldboard ploughing was carried out to a depth of about 23 cm. Mulch ripping (MR), was achieved by ripping to a depth of cm while maintaining the crop residues on the soil surface.

8 P a ge 8 Mulch cover at the beginning of the season ranged between 40 and 60 %. All treatments received annual fertiliser additions of 114 kg N ha-1, 22 kg P ha-1 and 25 kg K ha-1, the full experimental details are found in Moyo (2003). The addition of 5 t ha-1 manure more than doubled maize grain yield of the control, while the effect of mulch and reduced tillage on yield was marginal with a yield gain of only 0.2 t ha-1 over a nine year period. Results of Larbi et al., (2002) showed that the effects of mulch on maize grain yield were site specific and generally depended on the amount of mulch retained. Applying too much mulch causes waterlogging and induces immobilization of soil nutrients (Burrows and Larson, 1962). Manure application (5 t ha-1) under conventional tillage increased SOC by 0.13% and 0.09% per year on clay and sandy soils respectively, while the CA practice led to an increase of 0.02% per year for both sandy and clay soils. However, the quantities of manure applied are not achievable under smallholder farming systems. The quantity of manure produced from stover is a function of digestibility and feed intake. Given the low productivity of maize on smallholder farms of 1 t ha-1 and assuming that all is available for livestock feed with a digestibility of 56% (Tubei and Saidi, 1981), the amount of manure produced will be 440 kg i.e. ((100-56)/100) x 1000 kg. Assuming a 50% loss due collection and handling, about 200 kg of manure will be produced per ton of maize stover, hardly enough to contribute significantly to the improvement of soil organic carbon and nutrient supply. However, the opportunity cost of losing mulch is offset by gains in animal productivity given that communal grazing is not adequate during the dry season. The results suggest that the decision by farmers to allocate crop residues to animals as feed is most suitable for their circumstances because manure application in combination with fertilizer provides calcium, magnesium and micronutrients that ensure high yields especially on degraded soils. An optimal procedure for retaining adequate crop residues while providing sufficient feed for livestock is thus required to facilitate the adoption of CA on smallholder farms.

9 P a ge 9 Soil organic carbon accumulation in Conservation Agriculture: a review of evidence Corsi S1,2, Pisante M2, Kassam A1, Friedrich T1 1Food and Agriculture Organization of the United Nations, Rome, Italy; Sandra.Corsi@fao.org 2University of Teramo, Italy Concerns about rising atmospheric carbon dioxide (CO2) levels and climate change mitigation efforts have prompted considerable interest in recent years on world s soil carbon content: world s soils are estimated to have a high sink potential for carbon sequestration, not only in terms of their large carbon content, but also because soil organic carbon (SOC) is particularly responsive to modification through agricultural land use. However, the likely negative environmental impacts of the current tillage-based agriculture should not be assumed to be the same as the actual environmental effects that would occur under alternative agricultural systems. Much of the dominant traditional tillage agriculture (TA) in industrialised as well as developing countries is based on mechanical soil tillage with no organic matter mulch cover. This kind of agriculture is considered to decrease soil organic matter, increase soil compaction, flooding and erosion, especially in regions of higher or erratic rainfall, thus depleting soil quality and accentuating the cost of soil restoration. Further, tillage is highly energy-consuming operation that uses large amounts of fossil fuel per hectare (ha) in mechanised systems. In manual small scale systems, tillage requires high amount of human energy input and adds to the drudgery of farming. On the other hand, Conservation Agriculture (CA) is an agro-ecological approach to resource-conserving agricultural production that aims to achieve production intensification and high yields while enhancing the natural resource base. CA comprises the simultaneous application of three principles: i) minimum mechanical soil disturbance (with no-till or strip till and direct seeding); ii) permanent organic matter soil cover (with cover crops and/or crop residues); and iii) species diversification through crop associations and rotations (involving annual and/or perennial crops including trees). Scope and Approach of the Review The reported study was conducted using a multi-disciplinary analysis with the aim to developing a clear understanding of the impacts and benefits of the two aforementioned types of agriculture with respect to the CO2 fluxes and carbon pools, and examining if there are any misleading arguments at present in the scientific literature and highlight the evidence that exposes their flaws. This paper draws primarily on

10 P a ge 10 scientific papers published in leading peer-reviewed journals and the work of the Plant Production and Protection Division (AGP) of the Food and Agriculture Organization (FAO) working group on CA. A meta-analysis of the correlated literature has been undertaken and the cropping systems and research protocols followed by the researchers have been examined to explain any discrepancies. The study shows that when no carbon sequestration or even carbon loss are related to non-traditional agricultural systems, they are most frequently associated with: i) soil disturbance, ii) monocropping, iii) specific crop rotations, iv) poor management of crop residues, v) soil sampling extended deeper than 30 cm. In reality, CA is a broader agro-ecosystem management concept that requires compliance with the three abovementioned interrelated criteria. Most of the world s agricultural soils have been depleted of organic matter and soil health over the years under TA-based systems, compared with their state under natural vegetation. This degradation process has proved to be reversible and the main ways to increase soil organic matter content and improve soil health seem to be: i) keeping the contact and interactions between mechanical implements and soil to an absolute minimum, ii) using effective crop rotations and associations, and iii) returning crop residues as carbon source to the soil. The implementation of these practices can help restore a degraded agro-ecosystem to a sustainable and productive state. However, SOC sequestration is generally non-linear over time (Freibauer et al., 2004) and the effectiveness of conversion of TA to CA depends on many variables: for example, soil carbon sink strength increases most rapidly soon after a carbon-enhancing change in land management has been implemented, and reduces with time as the stable SOC stock approaches a new equilibrium (Smith, 2004). Even though some authors report significant increase in microbial activity soon after transition to CA, fuller advantages of CA can usually be seen only in the medium- to longer-term run, when CA practices become well established within the farming system. To provide an idea of the time scale, Smith reports that the period for European agricultural soils to reach a new steady state level, after a carbon-enhancing land-use change has been introduced, is approximately 100 years. The study discusses the effectiveness of using average rates for estimating carbon sequestration at the global level. In reality, there are different carbon pools in the soil undergoing transformation from the undecomposed form to decomposed stable form. The carbon sequestration potential of any soil, for the carbon pool considered, depends on the vegetation it supports (chemical composition of organic matter), soil moisture availability, soil mineralogical composition and texture, depth, porosity and temperature. Therefore, when addressing carbon sequestration, rates should always be referred to specific carbon pools, as each carbon category has highly different turnover rates. Further, the study examines the skeptical positions maintained by some researchers on CA s potential to offer productivity and ecosystem service benefits in dryland agricultural environments. Drylands major limiting factors are i) water deficiency, which is often

11 P a ge 11 worsened by unsustainable tillage-based land use practices, and ii) degraded soils, i.e. low fertility, associated with low levels of organic matter and nitrogen and soil life. One of the immediate effects of CA practices on soil moisture in semi-arid and arid regions is the improved capture and use of rainfall through increased water infiltration and decreased evaporation from the soil surface, with associated decreases in runoff and soil erosion compared to TA fields. With regard to the carbon budget, it should be noted that in CA systems in general the use of machinery is characterized by lower farm power requirements and the number of passes across the field is reduced relative to TA systems. This translates into less fuel consumption, lower working time and slower depreciation rates of equipment per unit area per unit of output. Additionally, with reference to residues restitution, when plant residues accumulate in situ, as under CA, the carbon fixed in vegetation through photosynthesis is potentially available as a net gain to the soil. In contrast, when the separation of plant residues from the harvestable components and their transport between fields is done by the use of machines, the energy cost and the CO2 released from fossil fuel combustion would need to be calculated. Also, the need for energy- and carbon-expensive nitrogen fertilizers can be reduced over time by the use of leguminous cover crops. Firstly these crops can directly influence the quantity of the carbon to be sequestered. Further, rotating or intercropping species with a variety of rooting depths and morphology helps to distribute organic matter throughout the soil profile. Lastly, the study reviews the effect of a shift from TA to CA on the carbon budget of main active green house gases (i.e. CO2, methane, nitrous oxide). This, along with sensible nitrogen management, reduces emissions and promotes SOC accumulation throughout the whole soil profile (Pisante et al. 2010). The lack of general consensus in the literature in this respect is largely due to two main reasons. First, it takes time to change soil composition at depth, while the superficial layer is more responsive to land management changes. Besides, when the carbon-enriched top layer (through fertilization) is turned upside-down, carbon concentration at the depth affected by ploughing may be higher than under CA. It should however be observed that, when turning the soil over, the recalcitrant carbon from deeper layers becomes exposed to rapid oxidation and mineralization at the soil surface, favouring SOC depletion in the top soil over time. Results and Discussion This paper concludes that terrestrial sequestration of carbon can efficiently be achieved by changing the management of agricultural lands from high soil disturbance practices to low disturbance. CA allows agro-ecosystems to store more CO2, emit less and all in all improve the ecosystem functioning and services, such as avoidance of runoff and soil erosion. These in turn result in: i) more aquifer recharge and regular stream flow from groundwater throughout the year and reliable yields of water from wells; ii) enhanced soil productive capacity and crop productivity; iii) less erosion and chemical loading, hence

12 P a ge 12 less sediment deposition and pollution downstream. The combined environmental benefits of CA contribute to global environmental conservation which also provides a low-cost option to help offset green house gases emissions (Lal, 1998). The main incentives for farmers to shift to CA are related to productivity and economic rather than environmental sustainability, i.e. improving farms competitiveness and cutting some of the most relevant production costs thereby increasing profit margins. With CA less or smaller tractors can be used and fewer passes over the field done, which also result in lower fuel and repair costs (FAO, 2001). In addition, over time, less N-fertilizer and pesticide are required for the same output. But then why are there still so many farmers using the plough? This review of the evidence shows that where TA is deeply rooted in the cultural background, and there is a lack of knowledge about CA principles and systems, it is particularly difficult for farmers to switch over to producing crops without ploughing or tilling. The shift to CA has been achieved where: i) pilot farmers have been informed of the system and convinced of its benefits by experience, ii) training on correct land management and implementation, as well as technical support to early adopters have been provided, iii) adequate support policies (e.g. funding through carbon sequestration contracts with farmers) have been implemented. With regard to policy support, according to the European Conservation Agriculture Federation (ECAF), in Europe, where CA does not exceed 1% of the agricultural cropland, things have slowly begun to change because the Common Agricultural Policy (CAP) since 2004 has been promoting sustainable agriculture systems for food safety and environmental sustainability but does not link environmental services to specific production systems. For SOC credits to become a structural part of the solution to mitigate climate change, short-term increases in SOC pool would need to be commodified and traded based on both on-site and off-site societal benefits. An example of a carbon offset scheme for agricultural land use has been in operation in Alberta, Canada. Alberta province, which has a strong agriculture-based economy that also has the highest green house gases emissions in the country, first adopted a climate change action plan in 2002, which since 2007 includes the implementation of a no-till based crop production system protocol on agricultural lands as an opportunity for direct and indirect reductions of green house gases emissions through carbon offset trading with industry. These important lessons learned from around the world regarding the high potential for carbon sequestration with CA systems and the associated opportunity for carbon trading should be taken into consideration in any climate change mitigation strategy for the future.

13 P a ge 13 BLWK/CAWC Webtuiste Die webtuiste is so opgestel dat enige iemand wat registreer (geen koste verbonde) foto s en videos kan oplaai en selfs vrae kan vra oor probleme wat hulle ondervind en dat antwoorde gegee kan word deur medeprodusente en kundiges. Daar sal ook n databank van die vrae gehou word as daar in die toekoms weer so n vraag opduik. Ons beplan ook om deur die loop van die jaar videos te maak en beskikbaar te stel, waar kundiges oor spesifieke onderwerpe gesels. Ek wil almal uitnooi om deel te raak van n lewendige webtuiste wat spesifiek gebou is om ons bewaringslandbougemeenskap in die Wes-Kaap te ondersteun. Toekomstige nuusbriewe sal ook op die webtuiste beskikbaar wees. Van volgende jaar af sal die nuusbrief slegs kort grepe uit artikels bevat en datums deurgee van groen en bruintoere. Die volledige artikels sal op die webtuiste beskikbaar wees. Die webadres is as volg: Sien julle almal aanlyn.

14 P a ge 14 INLIGTING TEN OPSIGTE VAN DIE BEWARINGSLANDBOUVERENIGING SE LEDEGELD Ons ledetal het aansienlik gegroei gedurende die jaar en het ons die 50 merk verbygesteek. Ons sal in die komende jaar fakture uitstuur aan huidige lede en andere vir die hernuwing van ledegeld of nuwe lidmaatskap. Ledegeld beloop R200 per plaas, met n maksimum van 2 lede wat toegelaat word, vir elke 2 bykomende lidmaatskappe sal n verdere R200 betaalbaar wees. Hierdie reëling geld ook ten opsigte van ander instansies soos chemiese agente ens. Aangeheg is die kontak besonderhede van ons finansiële mense. Indien iemand wil aansluit kan hulle net n e-pos stuur aan Gerty Mostert en dan sal sy vir julle n faktuur stuur. Die ledegeld gaan vir die instandhouding van die webtuiste. Asook vir verversings gedurende bruin en groentoere gedurende die seisoen. Kontakbesonderhede: BLWK/CAWC Gerty Mostert (gertym@elsenburg.com) Verskaf asb in die e-pos die naam van die plaas of instansie en die person aan wie faktuur uitgemaak moet word.