A. Kutuzova1, G. Blagoveschensky2, V. Stankov1 and M. Evtushenko3
1 All-Russia Research Institute for Forage Crops, 141470, Lugovala, Moscow Region, Russia2 Research Institute for Central Areas of the Non-Black Soil Zone, 143013 Nemchenovka, Moscow Region, Russia
3 Belorussian Agricultural Academy
Introduction
Materials and methods
Results.
Discussion and conclusions
References
Currently the grasslands of Russia are characterized by a sharp deficit of N; its removal increases its accumulation in by 3-4 times (Smurygin et al., 1985; Proskura et al., 1987). The most economical and efficient solution of this problem is thus to expand the use of biological N from legumes. Grass/legume swards ensure high energetic efficiency (Blagoveschensky, 1988). The experiments reported below investigated the efficiency of sowing method and tested different white clover varieties in pastures.
The experiments were carried out on sod-podzolic soils. The humus content was 1.8-2.0%, P content was 4-5 mg (100 g soil)-1, K content 9-11 mg (100 g soil)-1 and pH 6.0-6.1. The size of plot was 42-50 m2 with four replications.
Experiment 1 was used for testing white clover sowing methods (a) with the application of a milling direct drill in the sod of an 8-years-old pasture; (b) according to the common technology of the soil tillage, with a mixture of meadow fescue (Festuca pratensis Huds.), and timothy (Phleum pratense L.) under cover of an oat/forage pea mixture. Experiment 2 was implemented for testing four white clover varieties. The biological N accumulation was calculated according to the difference of the total N removed with yield. Grazing by cattle was also observed.
Productivity data from Experiment 1 are given in Table 1.
Table 1 Productivity of swards from different methods of sowing white clover (1989-91)
|
Sowing treatments |
Yield (t DM ha-1) |
ME (Hj ha-1) |
CP kg ha-1 |
|
Conventional |
6.09 |
60 |
1014 |
|
Sod seeding |
5.27 |
54.8 |
1039 |
During the first sowing year the EM productivity of the forage pea mixture was 4.92 t ha-1, for grass mixture, 2.16 t ha-1 and in the case of sod seeding 5.37 t ha-1. The energy expenditures for conventional sowing was 18.6 Hj ha-1 and in the case of sod seeding, 10.5 Hj ha-1. Dry matter yield, ME and CP yields from Experiment 2 are given in Table 2.
Table 2 Productivity of mixed swards with different varieties of white clover (1989-92)
|
White clover variety in mixture |
Yield (t ha-1 DM) |
ME (Hj ha-1) |
CP (kg ha-1) |
|
Jubilee |
7.23 |
74.2 |
1189 |
|
VIK 70 |
6.80 |
70.6 |
1139 |
|
Atoly |
6.64 |
68.5 |
1092 |
|
Volat |
7.02 |
72.4 |
1141 |
|
Grass mixture (N 180) |
8.50 |
76.2 |
1073 |
The productivity of the grass stand was 5.42 t ha-1. The variety Jubilee proved superior taking into consideration the yield of ME. The energy expenditure per kg CP in the case of grass/clover swards was 26.7-29.1 Mj, for 1 kg of ME, 428.6-464.2 and in the case of the grass mixture (N 180), 43.2 and 608.9, correspondingly.
The positive impact of sod seeding white clover in Experiment 1 was observed even during the second grazing. Taking similar grass swards into account, the productivity from sod seeding white clover is economically efficient according to the levels of energy expenditures and the time factor.
The varieties Jubilee and VIK-70 showed yield and persistence superiority; during the fourth year of utilization, yield was 0.3-0.6 t ha-1 EM higher than the other varieties. The introduction of clovers to seed mixtures increased the N content of pasture forage EM by 1.6-1.7%. The average consumption of such forage during a season was 44 kg per head while the average daily liveweight increment was 700-730 g head-1 without using concentrates.
BLAGOVESCHENSKY, G.V. (1988), Energy efficiency of feed production from grass. Vestnik s. Kh. nauki, No. 4 (380), pp. 61-67.
SMURYGIN, M., KUTUZOVA, A.A., (1985) Grassland should be fertilized. Journal of Russian Agriculture, No. 12, pp. 44-45.
PROSKURA, I. and KUTUZOVA, A.A. (1987). Utilization of biological nitrogen in grassland. International Agricultural Journal, No. 2, pp. 53-56.
