Spatio-temporal analysis of crop rotations and crop sequence patterns in Northern Germany: potential implications on plant health and crop protection

Abstract

Crop sequence patterns are considered as those schemes farmers apply within a single field to succeed crops over time, regardless of whether the same crop is grown continuously or a diverse rotation is used. This study aimed at identifying these patterns for a large and representative area in Northern Germany during a six-year period from 2005 to 2010. The analysis was carried out for the entire federal state of Niedersachsen (Lower Saxony) which has 1.8 million hectares of arable area.Field data was obtained by the Integrated Administration and Control System (IACS), which was developed for the administration of the European agricultural direct payments. So far, German IACS has not been exploited in the light of agronomical practice. In total, the available data comprised about 990 000 records for each year, each representing a single field out of the study region. Throughout the analysis, different agronomic and temporal scopes resulted in a different number of fields being accessible for evaluation. Ten major arable crops and crop groups were considered for the study; 184 701 fields representing 645 870 ha of arable area could be analyzed to identify crop sequence patterns over the six years. Thus, 16 836 combinations of the 10 major crops occurring in time and space could be described. Thereof, 12 crop sequence patterns were found covering 55.6% of arable area. For 2010, 619 447 fields representing 1 730 564 ha of arable area, were analyzed with regard to their respective crops and pre-crops. Maize, winter wheat, sugar beet, oilseed rape and potatoes were studied with special emphasis. On average, 46.9% of maize area were cropped following maize as a pre-crop. For winter wheat, self-sequences were identified on 30.0% of arable area. Oilseed rape and sugar beet are generally grown in typical rotations. However, 24.6% of arable crop area were considered as having a pre-crop which might be disadvantageous for crop health.Due to a rapid increase of maize area in the region, crop sequence patterns are undergoing a dramatic shift. It is concluded that a large proportion of arable area is potentially threatened by risks of pest and disease outbreaks as well as by economical over-reliance in a few cash crops. We demonstrate, that administrative data could offer many insights in agronomical trends and practices and should, therefore, be analyzed in more detail.

How Does Changing Pesticide Usage Over Time Affect Migrating Amphibians: A Case Study on the Use of Glyphosate-Based Herbicides in German Agriculture Over 20 Years

“…Together with the control of green biomass (volunteers and weeds, Agropyron repens in particular), these are considered to be the main drivers of GLY application (Raubuch and Schieferstein, 2002;Nail et al, 2007). In German crop rotations, rewardable winter cereals, such as winter wheat, winter barley and triticale, often follow winter rape (Steinmann and Dobers, 2013), and in accordance to our findings, field cultivation is often conducted in combination with GLY application. In 2009, winter rape was considered the major sink of GLY in Germany (Steinmann et al, 2012).…”

“…Some economically profitable crops, such as winter wheat, oilseed rape and silage maize, have increased, leading to narrower crop rotations and fewer crop species (Steinmann and Dobers, 2013;Destatis, 2015). Reducing the number of crops leads to more intensive peak-periods for conducting field cultivation and increases demands for higher working rates.…”

“…Higher rates and an increase in the application of herbicides, including GLY, are then necessary (Beckie, 2006). Narrow crop rotations may promote plant pests and diseases (Steinmann and Dobers, 2013). Controlling the green bridge between two successive crops to prevent the spread of pests or disease is particularly essential and often typically done using GLY.…”

Inter-relationships between crop type, management intensity and light transmissivity in annual crop systems and their effect on farmland plant diversity

“…During the last decade, new political frameworks for energy supply and agricultural production have led to large-scale changes in the relative frequency of major crop types grown in Western and Central Europe which fuelled the conversion of extensively managed fields, fallow land, pastures and meadows to intensively managed crop systems (Nitsch et al, 2012;Steinmann and Dobers, 2013). One major driver behind these changes are subsidies paid for the cultivation of energy crops (Charles et al, 2013;Khanna and Chen, 2013) which have been advocated by scientists and politicians as a tool to reduce CO 2 emissions for mitigating climate change (BMU and BMELV, 2010;IPCC, 2011).…”

Do farmers in Germany exploit the potential yield and nitrogen benefits from preceding oilseed rape in winter wheat cultivation?

“…Such strong concentration is not possible without growing wheat after wheat in the same field. In 2010, 30% of wheat was cultivated after wheat in the German state (Nomenclature of Territorial Units for Statistics level 1 (NUTS 1 level)) of Lower Saxony (NI) (Steinmann & Dobers 2013). In general, such monoculture is associated with deteriorated soil fertility, yield and yield stability.…”