The influence of different foliar fertilisation on the yield and botanical composition of a meadow sward

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1 The influence of different foliar fertilisation on the yield and botanical composition of a meadow sward Jankowska-Huflejt H. 1 and Klusek G. 2 1 Department of Meadow and Pasture, Institute for Land Reclamation and Grassland Farming (IMUZ) at Falenty, Raszyn, Poland. 2 Regional Centre of Agriculture Advisory in Modliszewice, Poland. Abstract During the years a study was carried out on a 3-cut meadow on mineral soil to compare the effects of different foliar fertilisation treatments on dry matter (DM) yield and botanical composition. Experimental treatments were allocated in a randomized block design with four replications of plots of 10 m 2 area established. These comprised 8 fertilisation treatments: 1.control (0), 2.NPK, 3.N + ½PK, 4.N + ½PK + foliar Ekolist PK, 5.NPK + foliar Mikrosol U, 6.NPK + complex foliar (Ekolist PK, Mikrosol U and Ekolist Mg); 7.NPK + foliar complex (Ekolist PK, Mikrosol U, Ekolist Mg) + Mikrosol Oz after the last regrowth; 8.N + ½PK + foliar Plonvit P. The highest DM yields were obtained from NPK fertilisation and after supplementary complex foliar fertilisation and complex and Mikrosol Oz. Comparable effects were observed in the case of N + ½PK and Ekolist PK foliar fertilisation. The changes of botanical composition were low: there was only a tendency of a positive influence of complex foliar fertilisation and Mikrosol Oz on persistence of favourable grasses, and of Ekosol PK and Plonvit on the persistence of legumes, mainly Trifolium repens L. Keywords: meadow, mineral soil, foliar fertilisation, yield of DM, botanical composition. Introduction There is increased interest in Poland in using foliar fertilisation, as a supplement to soil fertilisation, not only in intensive agriculture but also ecologically sensitive situations (Ciepiela et al., 1999). It can have great importance in extreme conditions and in plant-stressed situations, i.e. in periods of drought, excessive moistening, inadequate ph of soils, and also in situations where nutrients are yield-limiting foliar feeding can be supplementary to soil mineral fertilisation (Nurzyński, 1996). The aim of these investigations was to compare the effects of foliar fertilisation and top-dressing fertilisation on dry matter (DM) yield and to evaluate resulting changes in botanical composition. Material and methods The study was carried out during on a 3-cut meadow on a mineral soil (soil type was podsolic and pseudo podsolic, classified as valuation class IV b - characterised by a considerable mosaic, either periodically too dry or locally periodically too wet). Before establishment of the experiment (1999), the soil was ph 5.0 with low content of phosphorus (P) and high in potassium (K) and magnesium (Mg). The vegetation period typically lasts from 1 April to 1 November, the average annual temperature is 6.9 C, and precipitants mm. Experimental treatments were allocated in a randomized block design with four replications of plots of 10 m 2 area established. These comprised 8 fertilisation treatments: 1. without fertilisations (control), 2. NPK (N kg ha -1, P kg ha -1, K kg ha -1 ( ), 3. N+1/2PK, 4. N + 1/2 PK + foliar Ekolist PK (10 litre ha -1 ), 5. NPK + foliar Mikrosol U (2 litre ha -1 ), 6. NPK + complex foliar (Ekolist PK with urea 0.5% - in spring and after every regrowth - after the last one with urea 0.2%; Mikrosol U ha -1 + Ekolist Mg (5 litre ha -1 ) - after 5-7 days of Ekolist PK spraying), 7. NPK + complex foliar (as in treatment 6.) + before winter - Mikrosol Oz (2 1 ha N + 1/2 PK + foliar Plonvit P (10 litre ha -1 ).Every year the sward was cut three times and the DM yields were measured, the botanical composition of sward was evaluated (valuation method) and plant samples were taken for analysis of the chosen chemical compounds. Phenological observations and measurements of precipitants were conducted (Table 1). Composition of foliar fertilisers is shown in Table 2. They were applied in spring and after every harvest on plants with high above 10 cm. Doses of mineral fertilisers were: N -180 kg ha 1 (3 x 60), P 2O 5-70 kg ha 1, K 2O -160 kg ha 1 ( ). Sustainable Grassland Productivity 107

2 Table 1. Annual precipitation (mm) in years and precipitation in vegetation season recognized as optimal for grasslands. Months Optim. I II III IV V VI VII VIII IX X XI XII Table 2. Composition of fertilisers (g l -1 ). Component Foliar fertiliser Ekolist PK Mikrosol U Mikrosol Oz Ekolist Mg Plonvit P P K N Mg S Fe Mn Zn Cu B Mo Na Ti J Results and discussion The highest DM yields from the period of study (Table 3) were obtained after soil NPK fertilisation (treatment t ha -1 ), and then after soil NPK fertilisation supplemented with complex foliar fertilisation (treatment t ha -1 ) and complex with Mikrosol Oz before winter (treatment t ha -1 ). Table 3. Yields of DM ( t ha -1 ). Years Fertilisation treatments Total Mean 1. without fertilisation NPK N + 1/2 PK N + 1/2 PK + Ekolist PK NPK + foliar Mikrosol U NPK + foliar complex* NPK + foliar complex*+ Mikrosol Oz N + 1/2 PK + Plonvit P Standard deviation *Ekolist PK (on spring and after every cut with urea 0.5%, after the last cut with urea 0.2%), Mikrosol U + Ekolist Mg - after 5-7 days from spraying with Ekolist PK. 108 Grassland Science in Europe, Vol. 11

3 But in year with large deficiency in rainfall, (2001), especially in spring, effects of complex foliar fertilisation were annually about by 4-5% higher than effects of soil NPK fertilisation. Higher yields of Lolium perenne were reported from foliar fertilisation with urea, compared with soil fertilisation (Jankowski et al., 1994). Comparable DM yields (9.13 t ha -1 ) to the NPK treatment were obtained from treatment 4 (N + 1/2 PK + Ekolist PK) that is after replacement of part of soil fertilisation (PK) with foliar fertilisation. The increase of DM yield in relation to N + 1/2 PK fertilisation (treatment 3. - without Ekolist PK) was over 9%. The soil NPK fertilisation and foliar application of Mikrosol gave worse results, compared with both the NPK-only and the NPK supplemented by complex foliar fertilisation. The changes in botanical composition of sward were not large (Table 4). The contribution of grasses decreased slightly, most of all on the control (by 25%, mostly in favour of herbs and weeds), and in least range (by 2-3%) after supplementary foliar fertilisation, especially with Mikrosol U and Mikrosol Oz before winter. The share of legumes decreased also by over 50%, with the exception of the treatment with foliar fertilisation by Ekolist PK and Plonvit P, on which the decrease was 40%, and in case of Trifolium repens only by 20%. Table 4. Botanical composition of meadow sward before establishment of experiment (1999) and in Species/group of plant *Other grasses: Holcus lanatus, Poa annua, Agrostis vulgaris. ** Weeds and herbs: Taraxacum officinale, Plantago lanceolata, Matricaria chamomilla, Ranunculus repens, Rumex acetosella, Cardamine pratensis, Capsella bursa pastoris, Geranium pratense, Stelaria graminea. Conclusions The highest yields of DM were obtained after soil NPK fertilisation, and among treatments with foliar fertilisation after the complex foliar and complex with Mikrosol Oz before winter. These exceeded the DM yields after NPK fertilisation in one year with large deficiencies of precipitation. The replacement of half of the soil dose of PK by foliar Ekolist PK also gave comparable yields to full NPK soil fertilisation. Changes in botanical composition were small. There were tendencies for positive influence of the foliar complex fertilisation and Mikrosol Oz on the persistence of valuable grasses, and for Ekolist PK and Plonvit on the persistence of legumes, mostly Trifolium repens. References Before establishment of experiment control NPK N + 1/2 PK N + 1/2 PK + Ekolist PK Fertilisation treatments NPK+ NPK + foliar Mikrosol U complex. NPK + foliar complex + Mikrosol Oz N + 1/2 PK + Plonvit P Lolium perenne L Lolium multiflorum L Festuca pratensis Huds Phleum pratense L Poa pratensis L Other grasses* Grasses total Trifolium pratense Trifolium repens L Legumes total Herbs and weeds ** Ciepiela G. A., Jankowski K., Jodelka J. (1999) Dolistne dokarmianie roślin jednoliściennych. Nowoczesne Rolnictwo, 7, Jankowski K., Ciepiela G. A., Jodełka J. (1994) Wpływ dolistnego dokarmiania azotem na plon i niektóre właściwości chemiczne Ŝycicy trwałej. Wiadomości Melioracyjne i Łąkarskie, 3, 129. Nurzyński J. (1996) Pozakorzeniowe stosowanie nawozów mineralnych. VI Konf. P NawoŜenie roślin ogrodniczych - stan badań i kierunki rozwoju". Kraków 3-7 Sustainable Grassland Productivity 109

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