THE EFFECT OF CATCH CROPS AND NITROGEN ON THE CHEMICAL COMPOSITION OF BEET ROOTS

Vliv meziplodin a dusíku na chemické složení bulev cukrovky

U. Prośba-Białczyk, M. Mydlarski

Department of Crop Production, Agricultural University, Wrocław

Summary: In a four-year investigation on organic, stubble catch crop fertilisation of field bean, phacelia and mustard, and on nitrogen fertilisation at doses 0, 60, 120 and 180 kgN ha-1, the content of mineral components in the roots of three beet varieties (Atair, Kristall and PN Mono 4) was determined. The concentration of mineral components depended on fertilisation and variety genotype. Organic fertilisation induced an increase in the content of calcium, magnesium and zinc, and lowered the sodium concentration. Nitrogen at doses 120 and 180 increased the concentration of nitrogen and lowered that of phosphorus, calcium, magnesium and boron. The beet productivity depended on the level of mineral components in the roots. The content and technological yield of sugar was significantly and positively determined by the amount of phosphorus and magnesium as well as copper and boron, but negatively by the content of nitrogen, potassium and manganese. Sodium had a high positive effect on the root yield, whereas negatively on the content and yield of sugar.

Key words: sugar beet, catch crop, nitrogen fertilisation , variety, macro- and microelements

Souhrn: Ve čtyřletých pokusech s organickým hnojením strniskových meziplodin bobu, hořčice a svazenky a hnojení dusíkem v dávkách 0, 60, 120 a 180 kg N.ha-1, byl stanoven obsah minerálních složek v bulvách tří odrůd řepy (Atair, Kristall and PN Mono 4). Koncentrace minerálních složek byla závislá na hnojení a odrůdovém genotypu. Organické hnojení mělo za následek zvýšení obsahu vápníku, hořčíku a zinku a snížilo koncentraci sodíku. Dusík v dávkách 120 a 180 zvýšil koncentraci dusíku a snížil fosfor, vápník, hořčík a bór. Produktivita řepy závisela na úrovni minerálních komponent v bulvách. Obsah a technologický výnos cukru byl podstatně pozitivně ovlivněn množstvím fosforu, hořčíku, stejně jako mědi a bóru. Negativně působily dusík, draslík a mangan. Sodík měl pozitivní vliv na výnos bulev a negativně působil na obsah a výtěžnost cukru.

Klíčová slova: cukrovka, meziplodina, hnojení dusíkem, odrůda, makro a mikroprvky

Introduction

Availability in the soil and uptake of mineral components determine the productivity of beets, and their content in the roots is decisive for the technological value of the raw material obtained (Allison et al. 1997, Burba, Vlassak et al. 1991). Numerous studies indicate that dry matter content and concentration of mineral components in beet roots depend on variety, vegetation conditions and the production technology used (Allison et al. 1997, Gutmański and Nowakowski 1996, Gutmański and Mikita 2000, Prośba-Białczyk et al. 2001, Vlassak et al. 1991).

The aim of the investigation was to determine the effect of organic fertilisation with the stubble catch crop mass and with mineral nitrogen on the content of mineral components in the roots, as well as to find out the relation between their concentration and the yield level and some technological values of the raw material produced.

Materials and methods

In the years 1996-2000, in the climatic conditions of the Silesian Lowland, the chemical composition of three sugar beet varieties - Atair, Kristall and PN Mono 4- were analysed as dependent on organic fertilisation with stubble catch crops of field bean, phacelia and mustard, and on mineral nitrogen at doses 0, 60, 120 and 180 kg N/ha.

The investigations were conducted on a brown soil of fluvioglacial origin, of grey-brown podzolic type, formed of light clay on heavy clay, classified as good wheat complex.

The results of the investigation were analysed statistically with application of variance analysis, correlation and regression, at confidence level a = 0.05. No significant co-operation found between years and experimental factors allowed to present the results as mean values.

Results

A relation was found between concentration of some mineral components in the roots and the content and sugar yield (Tab. 1). The content of sugar depended positively on the phosphorus, calcium and magnesium concentration, as well as copper and boron. There was, however, a negative effect of the concentration of nitrogen, potassium and manganese on sugar content. The content of those elements also negatively affected the sugar yield and, except sodium, also negatively the technological sugar yield.

The concentration of the elements assayed depended on fertilisation and genotype of the varieties (Tab. 2, 3 and 4). Organic fertilisation with catch crops significantly affected the content of phosphorus, calcium, magnesium, sodium and zinc in the roots. Beet roots grown after phacelia had a lower concentration of phosphorus than those grown after mustard and without organic fertilisation. Beets cultivated without organic fertilisation had a lower concentration of calcium and magnesium in the roots and a higher sodium content. Beets grown after field bean contained more zinc than those grown after other catch crops and without catch crops.

The concentration of mineral components was affected by nitrogen fertilisation (Tab. 3 and Fig. 1). Nitrogen doses significantly differentiated the contents of nitrogen, phosphorus, calcium, magnesium and sodium, manganese and boron. The concentration of nitrogen in the roots increased only under the effect of nitrogen at 180 kg/ha, while that of sodium increased significantly with the consecutive, increasing doses of nitrogen. In relative terms, with respect to unfertilised roots, a documented increase in nitrogen content was 12 %, sodium 6.2 and 33 %, respectively. Nitrogen at doses 120 and 180 kg lowered the concentration of phosphorus, calcium, magnesium and boron, and induced a proven increase in zinc and manganese content.

The chemical composition of roots depended also on variety. Varieties differed in the content of phosphorus, potassium, calcium and sodium, as well as copper, zinc and manganese. The Mono 4 variety had, relative to other varieties, a significantly higher content of nitrogen and phosphorus, and of the microelements copper, zinc and manganese, but a lower concentration of potassium and sodium.

Table 1: Correlation coefficients for the relation between mineral components in the roots and yielding, and between the content and sugar yield

* r significant at level á=0,05; ** á=0,01, *** á=0,001

Table 2: Relation between mineral components and catch crop organic fertilisation

Table 3: Relation between mineral components and nitrogen fertilisation

Fig. 1: The effect of nitrogen fertilization on the content of mineral macrocomponents expressed in relative values

Table 4: Mineral components as dependent on variety

Conclusion

Concentration of mineral components in the roots depended significantly on variety genotype, catch crops organic fertilisation and mineral nitrogen fertilisation. Organic fertilisation induced increased content of calcium, magnesium and zinc, and lowered sodium concentration. Nitrogen at doses 120 and 180 kg/ha increased the concentration of nitrogen and sodium, and lowered phosphorus, calcium, magnesium and boron concentrations.

Phosphorus and magnesium, and copper and boron of the microelements, had a significantly positive effect on the content and technological yield of sugar. These features correlated negatively with the content of nitrogen, potassium and manganese.

Sodium contained in the roots had a significantly positive effect on the yield, but a negative effect on the content and yield of sugar. It did not correlate with the technological yield of sugar.

References

ALLISON M F. CHAPMAN J. L., GARAT C. E., TODD A. D. 1997. The potassium, sodium, magnesium, calcium and phosphate nutrition of sugarbeet (Beta Vulgaris) grown on soils containing incorporated straw. J. Sci. Food Agric. 74 (2): 216-220.

BURBA M. (1997). Perspectives of beet quality estimation: possibilities and limits. Mat. Konf. “Postęp w uprawie buraka cukrowego i jakości korzeni”. Warszawa. 59-73.

GUTMAŃSKI I., NOWAKOWSKI M.,1996 Wpływ dawki i formy azotu na wschody, plon i jakość przetwórczą buraków cukrowych w dwóch terminach zbioru. Biul. IHAR, 189, 41-49.

GUTMAŃSKI I., MIKITA J., (2000). Wpływ obornika i dawek azotu na wydajność i jakość przetwórczą korzeni buraka cukrowego oraz na zawartość azotanów w profilu glebowym w okresie wegetacyjnym. Folia Univ. Agric. Stetin. 211. Agricultura (84), 417-422.

PROŚBA-BIAŁCZYK U., REGIEC P., MYDLARSKI M.: (2001). Impact of nitrogen fertilisation on the technological value of sugar beet cultivar roots. Electronic Journal Of Polish Agricultural Universities. Volime 4, Issue 1, series Agronomy http.://www.ejpau. media.pl/series/volume4/issuel/agronomy/art-03.html

VANDERGETEN I.., VANSTALLEN M., (1991). Wirkung einer reihenweisen Plazierung von optimalen N-Mengen auf Ertrag und auf industrielle Qualität der Zuckerrübe. 54th Winter Congress of the International Institute for Sugar Beet Research, 297-319.

VLASSAK K., VANDERGETTEN I.P., VANSTALLEN M., (1991). Effect of nitrogen fertilizer placement on yield and quality of sugar beet. 54th Winter Congress of the International Institute for Sugar Beet Research, 455-463.

Adresa autora