Modelling structural changes in tilled topsoil over time as a function of cropping systems
| Autor: | H. Manichon, Guy Richard, J. Caneill, Jean Roger-Estrade, Hubert Boizard, Jean Boiffin |
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| Rok vydání: | 2000 |
| Předmět: |
Hydrology
Topsoil business.product_category Soil Science Soil science 04 agricultural and veterinary sciences 15. Life on land 010501 environmental sciences 01 natural sciences Soil compaction (agriculture) Plough Tillage Soil structure Loam Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Environmental science Soil horizon business 0105 earth and related environmental sciences |
| Zdroj: | European Journal of Soil Science. 51:455-474 |
| ISSN: | 1351-0754 |
| DOI: | 10.1046/j.1365-2389.2000.00323.x |
| Popis: | Summary The optimization of tillage practices requires the evaluation of the long-term effects of cropping on changes in soil structure. A model is presented that simulates changes in soil structure in the tilled horizons of cultivated fields. The indicator of soil structure that we have modelled is based on a morphological description of the structure and the assessment of the percentage of severely compacted zones and clods showing no visible porosity in the tilled layer of a soil profile. The model takes into account the spatial variation of the structure induced by traffic and tillage. Severely compacted zones are created under wheel tracks, they are cut and transferred during ploughing, and they are fragmented into fine soil during secondary tillage. The model was evaluated over 7 years in a field trial on loamy soil in three experimental plots, where the crop sequences and field operations induced contrasted changes in the percentage of severely compacted zones and clods. The model satisfactorily reproduced the changes with time of the indicator, and the correspondence between simulated and observed values was fairly good (r= 0.82, model efficiency = 0.61). However, some variations from one year to the next were poorly predicted. The sensitivity analysis did not suggest modification to the parameter values but showed that the performance of the model could be improved if the fragmentation (due to weather and tillage) were more precisely described in the model. Nevertheless the present version of the model and the corresponding simulation program (SISOL) can be used to compare the effects of different technical choices on the evolution of soil structure. |
| Databáze: | OpenAIRE |
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