Agro-economic prospects for expanding soybean production beyond its current northerly limit in Europe

Soybean is one of the five crops that dominate global agriculture, along with maize, wheat, cotton and rice. In Europe, soybean still plays a minor role and is cultivated mainly in the South and East. Very little is known about the potential for soybean in higher latitudes with relatively cool conditions. To investigate the agronomic potential and limitations of soybean for feed (high grain yield) and food (high protein content, e.g., for tofu production) in higher latitudes, an organic soybean cropping system experiment was carried out from 2015 to 2017 in northeastern Germany. The objectives were: (1) to identify food- and feed-grade soybean cultivars that are adapted to a central European climate in terms of protein, grain yield, and yield stability, (2) to explore the effect of irrigation on soybean protein and grain yield under relatively dry growing conditions, and (3) to determine the agro-economic potential of soybean cultivation for both feed and food markets. Three soybean cultivars were tested with and without irrigation. The soybean feed-grade cultivars 'Sultana' and 'Merlin' were better adapted to the growing cycle and temperature, providing higher and more stable yields (average 2700 kg ha(-1)) than the food-grade cultivar 'Protibus' (average 1300 kg ha(-1)). Irrigation increased soybean grain yields by 41% on average. In the year with sufficient precipitation, no additional irrigation was necessary. Gross margins of organic soybean ranged between 750 (sic) ha(-1) for the rainfed food-grade soybean and 2000 (sic) ha(-1) for the irrigated feed-grade soybean and were higher than other crops. We demonstrated a large agro-economic potential for soybean as a novel grain legume crop to diversify cropping systems and increase the production of protein crops in central Europe.Peer reviewe

Soybean Nodulation Response to Cropping Interval and Inoculation in European Cropping Systems

To support the adaption of soybean [Glycine max (L) Merrill] cultivation across Central Europe, the availability of compatible soybean nodulating Bradyrhizobia (SNB) is essential. Little is known about the symbiotic potential of indigenous SNB in Central Europe and the interaction with an SNB inoculum from commercial products. The objective of this study was to quantify the capacity of indigenous and inoculated SNB strains on the symbiotic performance of soybean in a pot experiment, using soils with and without soybean history. Under controlled conditions in a growth chamber, the study focused on two main factors: a soybean cropping interval (time since the last soybean cultivation; SCI) and inoculation with commercial Bradyrhizobia strains. Comparing the two types of soil, without soybean history and with 1-4 years SCI, we found out that plants grown in soil with soybean history and without inoculation had significantly more root nodules and higher nitrogen content in the plant tissue. These parameters, along with the leghemoglobin content, were found to be a variable among soils with 1-4 years SCI and did not show a trend over the years. Inoculation in soil without soybean history showed a significant increase in a nodulation rate, leghemoglobin content, and soybean tissue nitrogen concentration. The study found that response to inoculation varied significantly as per locations in soil with previous soybean cultivation history. An inoculated soybean grown on loamy sandy soils from the location Muncheberg had significantly more nodules as well as higher green tissue nitrogen concentration compared with non-inoculated plants. No significant improvement in a nodulation rate and tissue nitrogen concentration was observed for an inoculated soybean grown on loamy sandy soils from the location Fehrow. These results suggest that introduced SNB strains remained viable in the soil and were still symbiotically competent for up to 4 years after soybean cultivation. However, the symbiotic performance of the SNB remaining in the soils was not sufficient in all cases and makes inoculation with commercial products necessary. The SNB strains found in the soil of Central Europe could also be promising candidates for the development of inoculants and already represent a contribution to the successful cultivation of soybeans in Central Europe

Fostering the Implementation of Nature Conservation Measures in Agricultural Landscapes: The NatApp

Large-scale, high-input, and intensified agriculture poses threats to sustainable agroecosystems and their inherent biodiversity. The EU Common Agricultural Policy (CAP) covers a great number of nature conservation programs (Agri-Environment and Climate Measures, AECM) aiming to encourage sustainable agriculture. Currently, farmers are not encouraged to broadly implement these measures due to the lack of structured information, overly complicated and unclear application procedures, and a high risk of sanctions. In addition, the current structures are associated with time-consuming monitoring and control procedures for the paying agencies. Digital technologies can offer valuable assistance to circumvent relevant barriers and limitations and support a broader uptake of AECM. NatApp is a digital tool that supports and guides farmers through the complete process of choosing, applying, implementing, and documenting AECM on their fields in accordance with legal requirements in Germany. We introduce the concept of NatApp and analyze how it can simplify and encourage the uptake and implementation of AECM. This study identifies its unique features for the provision of information and documentation opportunities compared with other digital farming tools focused on sustainable agriculture and outline how it can support farmers to actively contribute to more sustainable agriculture

Orientation of tree rows in alley cropping systems matters – The “ShadOT” modelling tool for tree growth and shading effects

Agroforestry systems have received a significant attention in recent years and can be considered as a potential strategy in agricultural production to respond to worsening climatic conditions. The decision-making process for farmers to design and implement agroforestry systems is complex due to time-consuming processes of planting, growing and management of trees, as well as the long-term impacts on the field and its productivity. The shading of the arable land by trees is a core issue and should be reduced through a north-south orientation of the tree rows. However, this orientation is often in conflict with other criteria. In order to consider future shading from different tree row orientations into the design process, the modelling tool “ShadOT” was developed. This tool can simulate tree growth and analyses spatial shading over variable time periods by using only a limited number of parameters. This tool was programmed exclusively with open source software and can therefore be easily extended. It offers an ideal platform for testing different agroforestry designs due to its simple approach and minimal parameterization. Two different designs (north-south and west-east orientation) were tested for a field and differences in the temporal and spatial distribution of shaded areas are presented. • Modelling tool for tree growth and shading effects is presented. • The tool is written in Python programming language, uses only open-source software and requires a limited number of inputs. • Identification of spatial-temporal shading patterns of different alley cropping scenarios

Field path optimization to reduce headland and turning maneuvers at regional scales: automated detection of cultivation direction in the state of Brandenburg, Germany

Path planning for optimized field-work pattern is an important task within precision farming. The decision on a particular direction and path to cultivate and manage the field is complex and can significantly affect working time, energy consumption, soil compaction and yield. This study proposed a new method for automated detection of the current cultivation direction of several thousands of agricultural fields and compared the current cultivation direction with an optimized cultivation direction generated from a path planning algorithm. Airborne imagery from 2019 was analyzed using a modified Gabor filter. The identification takes place on a sub-plot level and can therefore detect small-scale differences in cultivation direction within fields. The method for identification of current cultivation direction had a high success rate of 87.5%. Fields with a high potential to save turning maneuvers and to reduce the area of headland were identified. From 3410 fields, a total of 58162 turning maneuvers and 507 ha headland were saved. This corresponds to 14.1% of all turning maneuvers and 7.6% of the total headland area for all analyzed fields in Brandenburg. A high optimization potential was demonstrated for field paths when efficient processing directions are taken into account. The method can be extended to the analysis of satellite imagery and thus offers the possibility of identifying current cultivation directions with a high spatial and temporal resolution. In future, this knowledge can be embedded within decision support systems for real-time optimization of field machinery path planning to support sustainable cropping practices

Ecosystem services and biodiversity of agricultural systems at the landscape scale

Peer Reviewe

Working with or against multifunctional landscapes? A case study of land users’ local knowledge of grassland–forest transition zones in northeastern Germany

Maintaining or restoring landscape multifunctionality is essential to ensuring that landscapes provide a broad array of services. Increased multifunctionality means that there are more diverse land uses bordering each other. The areas in which land uses interact are transition zones; those between grasslands and forests could fulfill multiple purposes due to their special ecological characteristics that support the needs of diverse species. However, with their management practices, local land users often shape the characteristics of land-use transition zones, with implications for ecological processes that build the base for service provision. Local ecological knowledge of land users could give important insights into the basis of their decisions. Here, we explore how land users’ and farmers’ local knowledge shapes their management that contributes to the maintenance and restoration of multifunctional landscapes. We conducted 21 semistructured qualitative interviews with livestock farmers and local experts for agriculture and nature conservation using grassland–forest transition zones as a specific example for interdependent components of multifunctional landscapes. We found that local knowledge of the interviewed farmers can contribute to the maintenance or restoration of multifunctional landscapes in several ways: it provides insight into landscape functions in grassland–forest transition zones, it enables land users to use landscape function-grassland production synergies, and it provides insight into the perceived negative and positive contributions of forests to grassland production. The perceived negative contributions of forests to grassland production were an important driver for farmers’ management decisions. Farmers have a holistic view of both the field and the landscape. Managing landscapes for multifunctionality is dependent on this kind of holistic knowledge to identify synergies and trade-offs in landscape functions and how they contribute to agricultural production. However, current regulations such as the institutional separation of grassland and forest and grassland area-dependent direct payments prevent farmers from acting according to their local knowledge

Patch cropping- a new methodological approach to determine new field arrangements that increase the multifunctionality of agricultural landscapes

Agricultural intensification decreased land cover complexity by converting small complex arable field geometries into large and simple structures which then were managed uniformly. These changes have led to a variety of negative environmental effects and influence ecosystem services. We present a novel small-scale and site-specific cropping system which splits a large field into small homogeneous sub-fields called ‘patches’ grouped in different yield potentials. A detailed workflow is presented to generate new spatially arranged patches with special focus on preprocessing and filtering of multi-year yield data, the variation in patch sizes and the adaptation of maximum working width to use available conventional farm equipment and permanent traffic lanes. The reduction of variance by the used cluster algorithm depends on the within-field heterogeneity. The patch size, the number of growing seasons (GS) used for clustering and the parallel shift of the patch structure along the permanent traffic lane resulted in a change in relative variance. Independent cross validation showed an increased performance of the classification algorithm with increasing number of GS used for clustering. The applied cluster analysis resulted in robust field segregation according to different yield potential zones and provides an innovative method for a novel cropping system

Influence of gypsum amendment on methane emission from paddy rice soil affected by saline irrigation water

To investigate the influence of gypsum application on methane (CH4) emission from paddy rice soil affected by saline irrigation water, two pot experiments with the rice cultivation were conducted. In pot experiment (I), salinity levels 30 mMNaCl (S30) and 90 mMNaCl (S90), that showed maximum and minimum CH4 production in an incubation experiment, respectively, were selected and studied without and with application of 1 Mg gypsum ha-1(G1). In pot experiment (II), CH4 emission was investigated under different rates of gypsum application: 1 (G1), 2.5 (G2.5) and 5 (G5) Mg gypsum ha-1 under a non-saline and saline condition of 25 mMNaCl (S25). In experiment (I), the smallest CH4 emission was observed in S90. Methane emission in S30 was not significantly different with the non-saline control. The addition of gypsum showed significant lower CH4 emission in saline and non-saline treatments compared with non-saline control. In experiment (II), the CH4 emissions in the saline treatments were not significantly different to the non-saline treatments except S25-G5. However, our work has shown that gypsum can lower CH4 emissions under saline and non-saline conditions. Thus, gypsum can be used as a CH4 mitigation option in non-saline as well as in saline conditions

Interactive Effects of Biochar, Nitrogen, and Phosphorous on the Symbiotic Performance, Growth, and Nutrient Uptake of Soybean (Glycine max L.)

Numerous studies reported the positive effect of soil amendment with biochar on plant development. However, little is known about biochar and its interrelation with nitrogen (N) and phosphorous (P) additions and their impact on plant growth. We carried out greenhouse experiments to understand the interactive effects of nitrogen and phosphorus supply, as well as biochar amendment, on the symbiotic performance of soybean (Glycine max L.) with Bradyrhizobium japonicum, and plant growth and nutrient uptake. The biochar was produced from maize by heating at 600 °C for 30 min and used for pot experiments at an application rate of 2%. Plants were fertilized with two different concentrations of P (KH2PO4) and N (NH4NO3). Biochar application significantly increased the dry weight of soybean root and shoot biomass, by 34% and 42%, under low nitrogen and low phosphorus supply, respectively. Bradyrhizobium japonicum inoculation enhanced the dry weight of shoot biomass significantly, by 41% and 67%, in soil without biochar and with biochar addition, respectively. The nodule number was 19% higher in plants grown under low N combined with low or high P, than in high N combinations, while biochar application increased nodule number in roots. Moreover, biochar application increased N uptake of plants in all soil treatments with N or P supply, compared with B. japonicum-inoculated and uninoculated plants. A statistical difference in P uptake of plants between biochar and nutrient levels was observed with low N and high P supply in the soil. Our results show that the interactions between nitrogen, phosphorus, and biochar affect soybean growth by improving the symbiotic performance of B. japonicum and the growth and nutrition of soybean. We observed strong positive correlations between plant shoot biomass, root biomass, and N and P uptake. These data indicated that the combined use of biochar and low N, P application can be an effective approach in improving soybean growth with minimum nutrient input