Sofia Larsson & J. Lindgren

One year grasslands (without timothy) compared to three year grasslands (with timothy) regarding quantity, forage quality and economy

Sofia Larsson and Johanna Lindgren

Rural Economy and Agricultural Society of Skaraborg, PO Box 124, SE-532 22 Skara, Sweden, sofia.larsson@hs-r.hush.se

Background

In Sweden production of silage is mainly carried out on swards lasting for three years or in many cases longer, with timothy as an important grass in the mixtures. Long-lasting swards can often lead to a decreased content of red clover over the years and an increased weed infestation which may cause large and undesired variations in both dry matter yield and in forage quality between years and between individual cuts. The aim with this study was to compare intensively cut swards lasting for one year with swards lasting for three years with timothy included. In the one-year leys species were used that have a high dry matter yield potential but that are more sensitive to climate in respect to over-wintering. The one-year swards were repeatedly incorporated and re-established every second year in the crop rotation. Dry matter yield, forage quality and the economy of the two systems were determined.

Materials and methods

Three field experiments were carried out in two different locations (Rådde and Uddetorp) in western Sweden and were established in 2001 and 2002. The leys were established by undersowing sown cereals in spring . The three-year grasslands (treatments C and D) were established with a fully grown cereal and the system with one-year swards was established in a cereal grown as forage, cut about two weeks after ear emergence. One-year leys (treatments A and B) were cut four times each year and three-year leys were cut three times. Swards lasting for one year were then tilled in the following autumn or spring and then again established as described. The experiments were carried out with four replicates. Yields were quantified in all plots for all crops in the rotations, also in forage of cereal and re-growth of the grassland (the year of establishment). Treatment-wise analyses of quality and botanical compositions were carried out each year. The species in the seed mixes were chosen by Svalöf Weibull AB and Scandinavian Seed AB (Table 1).

Table 1. Seed mixtures in the four treatments.

Swards lasting one year Swards lasting three years Treatment A: 15% red clover Fanny, 45% festulolium Paulita, 40% hybrid ryegrass Roxy (SW) Treatment C: 30% timothy Alexander, 30% meadow fescue Mimer, 20% perennial ryegrass Helmer, 10% red clover Sara, 10% white clover Sonja (SW 944)

Treatment B: 60% hybrid ryegrass Pirol, 40% italian ryegrass Fabio (SSd). In 2002 red clover was included in the mixture. Treatment D: 10 %timothy Lischka + 10 % Liglory, 10 %meadow fescue Preval, 30% festulolium Prior, 10% perennial ryegrass Herbie + 10% Fanda, 6% red clover Titus + 4 % Rajah, 5 % white clover Riesling + 5% Abercrest (SSd)

The results were evaluated with a model designed for calculating economical results per ha. The purpose of this model is to make it possible to evaluate different silage qualities from field experiments with all measured variables included and thereby report the results in a clearer and more instructive way (Gruvaeus, unpublished). The program optimizes the

cheapest feed ratio and the value of different silages is stated against a defined standard quality of silage (value/price for 1 MJ in barley). Treatments A and B were fertilized with 100+80+70+50 = in total 300 kg nitrogen ha-1 and C and D were fertilized with 80+70+50= 200 kg N ha-1. The cost of each year as grassland was estimated according to figures shown in Tables 2 and 3. The harvesting cost was then estimated depending on the amount of forage.

Table 2. Expenses in treatment A and B. Expenses Quantity Price SEK ha-1 Sowing 100 % 300 Seed 100 % 18 28.00 504 Nitrogen Axan 27-4 kg ha-1 815 2.30 1874 Nitrogen N-34 kg ha-1 235 2.45 576 Cost of fertilizing 305 Cost per year of ley except harvest Treatments A and B 3559

Table 3. Expenses in treatment C and D.

Expenses Quantity Price SEK ha-1

Sowing 33 % 66

Seed 33 % 18 28.00 199

Nitrogen Axan 27-4 kg ha-1 740 2.30 1704

Cost of fertilizing 224 Cost per year of ley except harvest Treatments C and D 2193

Results and discussion

The forage produced from each growing system was included in the summary of both yield and income. The one-year sward yields over the period of three years produced nearly 36 Mg dry matter (DM) ha-1 in the experiment at Uddetorp and over 29 and 24 Mg DM at Rådde In the same experiments, the three- year swards produced almost 31 Mg DM at Uddetorp and over 26 and 23 Mg DM at Rådde. The difference in gross income (except for the higher cost for tillage in A and B) for each year with grassland was 3700 SEK ha-1 at Uddetorp, or to the good for the short-lived swards. The experiments at Rådde showed the opposite result. At Rådde, the three-year swards showed the highest income and the difference in gross income was -300 and -1 400 SEK ha-1 . The reason was probably the more difficult winter conditions at Rådde compared to Uddetorp. These comparisons were based on two replicates per system. The system with one-year leys is therefore possibly feasible in a small part of Sweden where there is little or no problem with winter conditions. There must also be fields with little or no problems with stones, in other words in a very small part of Sweden. For the major part of Sweden timothy still plays an important role in the grasslands.