ISHS Acta Horticulturae 563: International Conference on Environmental Problems Associated with Nitrogen Fertilisation of Field Grown Vegetable Crops
EFFECT OF SOIL AERATION ON NITROGEN AVAILABILITY AND GROWTH OF SELECTED VEGETABLES-PRELIMINARY RESULTS |
| Authors: | H. Heuberger, J. Livet, W. Schnitzler |
| Keywords: | cauliflower (Brassica oleracea L. convar. botrytis (L.) Alef. var. botrytis L.), sweet corn (Zea mays L. convar. saccharata koern.), drip irrigation, subsurface drip irrigation, fertigation, nitrate, N uptake, plant sap analysis |
| Abstract:
After heavy rainfall or irrigation, the macropores of the soil are filled with water leading to limited gas diffusion and reduced oxygen content of the soil air for a certain period of time. In this situation, soil aeration by means of forced injection of atmospheric air into the soil via a subsurface drip irrigation system, is thought to accelerate the depletion of water from macropores and increase the oxygen concentration in the soil air. In 1999, cauliflower (Brassica oleracea L. convar. botrytis (L.) Alef. var. botrytis L.), cv. 'Fargo' and sweet corn (Zea mays L. convar. saccharata Koern.), cv. 'Tasty Sweet' were grown in a silty clay loam under varying drip irrigation, fertigation, and aeration conditions. The drip laterals for irrigation (S-I) and fertigation (S-F) were placed 5 cm below the soil surface. In another fertigation treatment (Sub-F) and for fertigation cum aeration (Sub-F-A), the laterals were placed at 15 cm soil depth (Subsurface). Nitrogen fertilisation was 250 kg N/ha for cauliflower and 180 kg N/ha for sweet corn with basal application and top dressing in S-I and fertigation after basal application in the fertigated treatments. Available N, which was defined as nitrate in the rooting zone, did not differ between the three fertigation treatments. Nitrate in the sap of cauliflower petioles was determined from 7 weeks after planting until harvest. It always showed slightly but not significantly higher nitrate concentrations in the aerated compared to the non-aerated cauliflower. N uptake and total fresh weight and product weight of cauliflower did not differ among treatments. In the sweet corn section of the experimental field, a waterlogged area disturbed field uniformity but revealed the positive effect of fertigation combined with aeration by more vigorous corn crop and higher cob yield compared to S-I (single-plot comparison). | |
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