Crop rotations for grain production

There is an increasing demand for organically grown cereal grains in Denmark, which is expected to cause a change in the typical organic farm structure away from dairy farming and towards arable farming. Such a change may reduce the stability of the farming systems, because of decreasing soil fertility and problems with weed control. There have only been a limited number of studies under temperate conditions in Europe and North America, where different crop rotations have been compared under organic farming or similar production conditions

ECONOMIC IMPACT OF INTRODUCING ROTATIONS ON LONG ISLAND POTATO FARMS

Potatoes have been grown continuously on many Long Island (New York) fields. Environmental concerns have raised questions about the continued usage of this practice. A farm-level linear programming model was used to investigate the economic impacts of crop rotations which result in reduced potato acreage. Crop rotations (an Integrated Pest Management tactic) reduced total pesticide use, but also reduced returns above variable costs as successively stringent rotation requirements were forced into the solution. The crop rotations which caused the least effect on income were identified.Resource /Energy Economics and Policy,

Modelling crop rotations of organic farms

With the described holistic model approach it is possible to generate agronomically-suitable and detailed 3-8 year crop rotations for diluvial sites in north-eastern Germany under the special demands of organic farming systems with and without livestock production. The stand-alone version can be used for crop rotation planning at the farm level. In addition, this model version may be applied for studying the influence of the parameter and estimation algorithm ranges within the model on the complex interactions between site condition, cropping methods and the rotational cropping systems. Sensitivity analyses show those model parameters and estimation algorithms which have to be managed with special care and those for which further research is needed

Nitrate leaching from arable crop rotations in organic farming

The crop rotation is a crucial and integral part of organic farming systems. It must be designed to maintain and exploit soil fertility, and to minimise the impacts on environment, e.g. through nitrate leaching. Crop rotations in organic farming typically include legume crops to provide nitrogen fixation and improve soil fertility. Catch crops are also commonly used, if demands for soil tillage to control perennial weeds allow. This paper presents results on nitrate leaching from a field experiment with comparison of three different crop rotations with and without catch crops designed for organic farming

Einfluss verschiedener Fruchtfolgen viehhaltender und viehloser Systeme auf Ertrag und Produktivität: Ergebnisse eines Dauerfeldversuches

In organic crop rotations proportion, use and type of legumes have a different effect on subsequent crops. The yield of subsequent cash crops is affected by the farming system (livestock with organic fertilizer or stockless) and the temporal distance of the cash crop to the legume. To investigate the intermediate- and long-term effects on yield and productivity, a long-term field trial with six crop rotations was established in 1997 in Viehhausen, Upper Bavaria (one crop rotation with a period of 5 years, five crop rotations with 3 years). The present report tested these crop rotations regarding yield and productivity for the years 2000 to 2010. Significant differences were determined in productivity when legumes were included into the calculation. Crop rotations with grass-clover leys in meadow mowing (with livestock) and the return of the nutrients as manure had the highest productivity. The crop rotations with grain legume showed the same productivity as crop rotations with mulched grass-clover leys

Productivity and N-leaching in organic dairy grass-arable crop rotations

Increasing size of organic dairy farms makes grazing of all cropped land inexpedient due to long distance to the milking facilities. We investigated nutrient dynamics and feed production in two dairy crop rotations with differences in proportion of grazing and cutting. One six year crop rotation represents close to the farm buildings (barley undersown with grass-clover - 4 years of grass-clover - spring barley/catch crop) and another represents further away (barley undersown with grass-clover, 2 years of grass-clover -barley/catch crop - maize/catch crop - lupin/catch crop). In each of the crop rotations was made five treatments concerning grazing/cutting strategy and manure application. Results shows that herbage production was high in year 1-4 of grass-clover. Nitrate leaching in the crop rotations were highest in grazed and manured 2-4 years old grasslands, but also following maize and lupin considerable losses occurred despite the presence of catch crops. Following grassland cultivation, a barley silage crop undersown with Italian ryegrass reduced leaching to a minimum

Optimising Broadacre Crop Rotations using Dynamic Programming

A Dynamic programming Model is used to select the most profitable crop rotation from seven crop alternatives including pasture. Crop yields within a rotation are estimated by specifying growing season rainfall, water use efficiency and weed and disease penalties caused by the three previous years crop history. A provision exists to include the effect on yield of other natural resource limitations. Regional variations can be accounted for by varying rainfall, management practices, yield penalties and input costs. A nitrogen-phosphorous calculator ensures sufficient fertiliser is applied for the crop to achieve its expected yield. This approach can be used to measure the productivity implications of advances in technology as well as the impact of rainfall, yield and price variations on optimal rotations.Crop Production/Industries,

Crop Rotations - 1968 Viewpoint

Results and practice and show selected crop selected crop sequences are the modern concept in crop production. With some exceptions, technology provides the same factors as rotations do - and is more profitable