The influence of crop rotation and soil tillage on seed population dynamics of A vena sterilis ssp. ludoviciana |
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| Authors: | L NAVARRETE C FERNANDEZ QUINTANILLA |
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| Institution: | Servido de Investigacion Agraria, Communidad de Madrid, Apartado 127. Alcala de Henares 28880, and;Centro de Ciencias Medioamhientales, CSIC, Serrano 115, 28006 Madrid, Spain |
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| Abstract: | The dynamics of seed populations of Avena sterilis ssp. ludoviciana (Durieu) Nyman in plots maintained under different crop rotations and tillage systems was studied over a 5-year period. The seed reserves buried in the soil were practically depleted during this period by using any of the three cropping systems evaluated. No significant differences were found between using a continuous barley rotation with annual application of herbicides and using a barley:fallow rotation with herbicides applied only as needed. The decline in seed populations was not affected by the tiliage system used during the fallow period (ploughing or no tillage). The tillage practices used in the various treatments, combined with the variable seed output from each treatment, resulted in different vertical distribution of the seeds in the soil profile. Shallow cultivation resulted in an accumulation of seeds in the upper soil layers; in contrast, a large proportion of the seeds were buried and maintained below 15 cm in the ploughed treatments. Although the seed distribution patterns produced by the various tillage systems had an effect on seedling recruitment, the largest changes in this parameter were associated with the different cropping sequences. Four times more seedlings were recruited in years under barley cropping than in those under fallow. |
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