Pro's and con's of reduced tillage in maize with respect to weeds Rommie van der Weide Hilfred Huiting, Piet Bleeker en Marleen Riemens

Why reduced tillage? Which reduced tillage systems? Research and results First conclusions Future Content

Why reduced tillage?

Economic advantages: Fuel savings (15 till 80%) Less labour (till 60%) Less machinery costs (but first new investments) Higher supporting power of the soil On term savings in nutrients

Less emission of CO 2, N 2 O, CH 4 Extra carbon in the soil up to 0.2 t. ha -1. y -1 C Better drought tolerance (1% o.s. = 150 m3/ha) Better water infiltration and less erosion (>90% by no till and >60% by non inversion tillage) Better surfacewater quality through less superficial emission of nutrients and pesticides Less emission of CO 2, N 2 O, CH 4 Extra carbon in the soil up to 0.2 t. ha -1. y -1 C Better drought tolerance (1% o.s. = 150 m3/ha) Better water infiltration and less erosion (>90% by no till and >60% by non inversion tillage) Better surfacewater quality through less superficial emission of nutrients and pesticides Environmental advantages:

Creating More Competetive Alternatives and Tecnologies: Sustainable Farming In Brasil Creating More Competetive Alternatives and Tecnologies: Sustainable Farming In Brasil Efficiency: Fuel Ploughing = 1 lt for 50 kg kernels No Till = 1 lt for 96 to 123 kg kernels Nutrition: NPK Ploughing = 1 kg for 15 kg kernels No Till = 1 kg for 26 kg kernels Efficiency: Fuel Ploughing = 1 lt for 50 kg kernels No Till = 1 lt for 96 to 123 kg kernels Nutrition: NPK Ploughing = 1 kg for 15 kg kernels No Till = 1 kg for 26 kg kernels

Loss of organic matter in convencional, but increase with no till Loss of organic matter in convencional, but increase with no till

Which reduced tillage systems?

Ploughing and culture measures Ploughing and seedbed preparation are important measures with respect to weed control Economic and environmental benefits result in increased reduced tillage (95 M ha) (New) technical developments thereby serving the weed control (e.g. ridge till Cloutier, 2007)

In the Netherlands non inversion tillage in some areas If needed loosening the soil in autumn cultivation in various ways, often in combination with a powered tool (harrow or cultivator)

Ridge tillage in Canada/USA (permanent ridges)

Ridge tillage Before and after sowing on permanent ridges and sowing machine

Physical weed control in case of crop residues

Strip tillage machinery (Dutch Pol/Kuipers)

No till and direct seeding: Loosening the soil by: increased soil fauna rooting (green manure) crops Soil coverage for: erosion prevention weed control possibilities for precision spraying Loosening the soil by: increased soil fauna rooting (green manure) crops Soil coverage for: erosion prevention weed control possibilities for precision spraying

Research and results

Objectives to investigate the usability of ridge till /no till systems as recently developed in the US and Canada for Dutch conditions; to investigate the interaction of tillage system, weed control method and green manure crops choice; to investigate the consequences for weed control, crop protection and economical and environmental aspects.

In 2009 start multiple years experiment maïze in Lelystad (EL&I and SPF) Before several years grassland at marine loam soil Start with main treatments (in 3 replicates): Ploughing Ploughing with a caterpillar Non inversion tillage Ridgetill No till Experimental strips with f.e. strip tillage Sub treatments: 4 different green manure crops and no/weedy in fallow period Two different weed control methods Experiment total 180 fields on 2 ha.

Mechanical weed control

Results 2009 ObjectWeed control Rel. fresh yield (57.7 t/ha) Rel. dry yield (18.9 t/ha) Rel. VEM yield (18.5 t/ha) % (weed) cover PloughingChem Mech N.I. tillageChem Mech Ridge tillageChem Mech No tillChem Mech Strip tillChem Strip till no RRMech Strip till no RRMow N.I. till no RRMech

Results 2010 ObjectWeed control Rel. fresh yield (53.0 t/ha) Rel. dry yield (17.5 t/ha) Rel. VEM yield (16.2 t/ha) % (weed) cover PloughingChem Mech N.I. tillageChem Mech Ridge tillageChem Mech No tillChem Mech Strip tillChem Strip till no RRMech Strip till no RRMow N.I. til no RRMech

Weed cover % with different green manure crops: ObjectTreatmentRye Oilseed rape No/ weedy grass/ cloverHairy vetch ploughchem mech NI tillagechem mech Ridgetillchem mech No tillchem mech

First conclusions

Several soil cultivation systems gave comparable yields in case the green manure was killed with Roundup. No till resulted in yield reduction during the first years. For organic farming non inversion tillage instead of ploughing is possible. Mechanical equipment should be adapted to green manure residues on the soil surface (e.g. moving harrows). No till and strip till are difficult to manage organic and avoid yield losses. More weeds left in case of non inversion tillage (2-3 times) instead of ploughing in the second year. Also green manure crop choice influences weed pressure (less after rye and oilseed rape).

Reduced tillage systems will gain importance in Europe because of economic en environmental contraints. The different opportunities need to be optimized and compared on a longer time scale, not only concerning yields, weeds and economics but also on the environmental effects. Precision techniques (for sowing, nutrition and crop protection) can be used for further improvement. Future:

Thank you for your attention, discussion and (further) support! © Wageningen UR

Relative VEM with different green manure crops: ObjectTreatmentRye Oilseed rape No/ weedy Grass/ cloverHairy vetch ploughchem mech NI tillagechem mech Ridgetillchem mech No tillchem mech

First calculations energy usage in MJ/ha Object Ploughing630 Non inversion606 No till215

C C Infiltration Conventional Tillage Conventional Tillage * *