@article{BoeneckeMeyerVogeletal.2020, author = {B{\"o}necke, Eric and Meyer, Swen and Vogel, Sebastian and Schr{\"o}ter, Ingmar and Gebbers, Robin and Kling, Charlotte and Kramer, Eckart and L{\"u}ck, Katrin and Nagel, Anne and Philipp, Golo and Gerlach, Felix and Palme, Stefan and Scheibe, Dirk and Zieger, Karin and R{\"u}hlmann, J{\"o}rg}, title = {Guidelines for precise lime management based on high-resolution soil pH, texture and SOM maps generated from proximal soil sensing data}, series = {Precision Agriculture}, volume = {22}, journal = {Precision Agriculture}, publisher = {Springer Nature}, issn = {1385-2256}, doi = {10.1007/s11119-020-09766-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-4890}, pages = {493 -- 523}, year = {2020}, abstract = {Soil acidification is caused by natural paedogenetic processes and anthropogenic impacts but can be counteracted by regular lime application. Although sensors and applicators for variable-rate liming (VRL) exist, there are no established strategies for using these tools or helping to implement VRL in practice. Therefore, this study aimed to provide guidelines for site-specific liming based on proximal soil sensing. First, high-resolution soil maps of the liming-relevant indicators (pH, soil texture and soil organic matter content) were generated using on-the-go sensors. The soil acidity was predicted by two ion-selective antimony electrodes (RMSEpH: 0.37); the soil texture was predicted by a combination of apparent electrical resistivity measurements and natural soil-borne gamma emissions (RMSEclay: 0.046 kg kg-1); and the soil organic matter (SOM) status was predicted by a combination of red (660 nm) and near-infrared (NIR, 970 nm) optical reflection measurements (RMSESOM: 6.4 g kg-1). Second, to address the high within-field soil variability (pH varied by 2.9 units, clay content by 0.44 kg kg-1 and SOM by 5.5 g kg-1), a well-established empirical lime recommendation algorithm that represents the best management practices for liming in Germany was adapted, and the lime requirements (LRs) were determined. The generated workflow was applied to a 25.6 ha test field in north-eastern Germany, and the variable LR was compared to the conventional uniform LR. The comparison showed that under the uniform liming approach, 63\% of the field would be over-fertilized by approximately 12 t of lime, 6\% would receive approximately 6 t too little lime and 31\% would still be adequately limed.}, language = {en} } @article{RuehlmannBoeneckeGebbersetal., author = {Ruehlmann, Joerg and B{\"o}necke, Eric and Gebbers, Robin and Gerlach, Felix and Kling, Charlotte and L{\"u}ck, Katrin and Meyer, Swen and Nagel, Anne and Palme, Stefan and Philipp, Golo and Scheibe, Dirk and Schr{\"o}ter, Ingmar and Vogel, Sebastian and Kramer, Eckart}, title = {Predicting the Base Neutralization Capacity of Soils Based on Texture, Organic Carbon and Initial pH: An Opportunity to Adjust Common Liming Recommendation Approaches to Specific Management and Climate Conditions}, series = {Agronomy}, volume = {13}, journal = {Agronomy}, number = {11}, editor = {Ciavatta, Claudio}, publisher = {MDPI}, issn = {2073-4395}, doi = {10.3390/agronomy13112762}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-9435}, abstract = {

Liming is an effective measure to increase the soil pH and to counterbalance soil acidification. Therefore, the liming recommendations (LRs) for agricultural practice consider two aspects: changing the initial pH to the desired pH and compensating for all pH decreases taking place within the liming interval. The separation of these aspects is essential to optimize LRs and to minimize lime losses to the environment. Therefore, we developed a pedotransfer function (PTF) to calculate the lime demand to change the initial pH to the desired pH and compared the results with the LRs for agricultural practice. Applying this PTF to a set of 126 soil samples that were analyzed for base neutralization capacity could explain approximately 78\% of the variability in the pH changes after the addition of different amounts of Ca(OH)2. Consequently, the lime demand to change the initial pH to the desired pH increased by approximately one-sixth compared to the lime demand proposed by the liming recommendation scheme, which is commonly used in Germany. From the numerical difference between the lime demand according to the LRs and the PTF, we calculated the annual acidification rates based on the soil texture, organic matter content and initial pH. Decoupling the abovementioned two aspects of LRs might be helpful to optimize the LRs by adapting to different regions, diverse management strategies and a changing climate.

}, subject = {-}, language = {en} }