Abstract: The forage yield and quality of common vetch, hairy vetch, hungarian vetch and triticale grown alone and as mixtures of legume + triticale were investigated in Black Sea costal area in Samsun, Turkey in the 2002-2003 and 2003-2004 growing seasons. The experiment design was Randomized Block Design with three replications. The highest green forage (32.94 t ha-1), dry matter (6.23 t ha-1) and crude protein yields (1.06 t ha-1) were obtained from the mixture including 70% hairy vetch + 30% triticale. It was determined that 80% hairy vetch + 20% triticale mixture had the highest vetch rate in dry matter. The mean land equivalent ratio values of dry matter yield was 1.45. In conclusion, the 70% hairy vetch + 30% triticale mixture in arid seasons, 70% common vetch + 30% triticale in rainfall seasons can be recommended in the similar ecologies because of theirs high forage and crude protein yields.
INTRODUCTION
In the Black Sea region except Samsun, fields are quite rough and, therefore, difficult to cultivate for agricultural purposes. Main crops such as corn, sunflower, tobacco, soybean, and sugar beet are grown in the region in summers. In the region, since fields are planted with either vegetables or left empty from October to May, there is a great opportunity to grow some forage such as vetch during this period[1]. The vetch in annual leguminous forage is one of the most widespread genuses cultivated[2]. It has ability to fix atmospheric free nitrogen into the soil by symbiotic living with bacteria of Rhizobium species and sustaining of soil fertility[3]. Because of having weak and thin stem, the vetches spread. So harvest gets difficult and due to lossing leaves, its forage and quality decrease[4,5]. Vetch should be sown mixture with cereals in order to overcome spreading[6,7]. When vetches having high protein content grow mixture with the cereal having high starch content, it composes quality and easy digestible forage[8,9]. But, in the vetch mixtures with cereals, it is essential to be known the rates of the vetch and cereal species on high forage yield and forage quality. Because high cereal rate in botanic composition of legume + cereal mixture cause low protein content which is one of the most important factors to determine the forage quality[6].
The objective of this study was to determine the suitable mixture rate of vetches and triticale grown under Black Sea costal area in Turkey conditions.
MATERIALS AND METHODS
This study was conducted in the experimental area of Black sea Agricultural Research Institute, Samsun, Turkey (41°21′ N, 36°15′ E, altitude 4 m) in 2002-2003 and 2003-2004. Climatic data for the research area are given Table 1. Soil was clay-loam, pH 7.1; organic matter 2.05 g kg-1; available P, 21 g kg-1; available K, 93 g kg-1. Common vetch (Vicia sativa L.) Cv. “Kubilay-82”, hairy vetch (Vicia villosa Roth.) Cv.“Menemen-79”, hungarian vetch (Vicia pannonica Crantz.) “population” and triticale (Triticosecale) Cv. “Tatlicak-97” were used as plant materials.
The field trials started on 3 November of first year and 1 December of second year and were carried out in a randomized complete block design with three replications. Pure common vetch, hairy vetch, hungarian vetch and triticale, 80% vetch + 20% triticale, 70% vetch + 30% triticale, 60% vetch + 40% triticale and 50% vetch + 50% triticale mixtures were sown. Each plot was 6 m2. Seeding rates of pure common vetch, hairy vetch, hungarian vetch and triticale were 120, 80, 100 and 200 kg ha-1, respectively. When the legumes had 50% flower, the plots were harvested for forage yield. Subsamples were dried at 70°C for 48 h to determine dry matter yield. After vetch and triticale samples had dried, they were weighed one by one. So, it was determined vetch rate in dry matter of mixture. Crude protein analyses were determined on ground subsamples of legume and triticale hays. According to the micro-Kjeldahl procedure described by Nelson and Sommers[10], the nitrogen concentration of the hay was determined, and crude protein concentration was calculated (N x 6.25).
Land Equivalent Ratio (LER) was defined as the relative area of a monocrop plant required to have the same yield obtained from its mixture. LER was calculated by using the formula given below[11,12];
Analysis of variance was performed on forage yield and its components data using the SAS[13] program. Means were compared using Duncan’s Multiple Range Test.
RESULTS AND DISCUSSION
Green forage yield: Highly significant differences were found in green forage yield: 11.60 to 34.33 t ha-1 in the first year and from 11.15 to 34.16 t ha-1 in the second year (Table 2). Average green forage yield varied from 11.37 t ha for pure triticale to 32.94 t ha for 70% hairy vetch + 30% triticale (Table 2). In the first year, the highest green forage yield (34.33 t ha-1) was obtained from the mixture containing 70% hairy vetch and 30% triticale. In the second year, the highest green forage yield (34.16 t ha-1) was obtained from the mixture containing 70% common vetch and 30% triticale (Table 2). The total precipitation in 2003 was lower than in 2004. Soya et al.[14] reported that the highest forage yield had been obtained from hairy vetch+cereal mixtures and common vetch+cereal mixtures in arid and rainfall seasons, respectively. The forage yields obtained from mixtures were almost higher than pure sowing yields. The similar results have been reported by other researchers[15-18].
Dry matter yield: The dry matter yields of the pure sowings and mixtures were significantly different (p<0.01) in both years. There were no differences between the years (Table 2). In the first year, the highest dry matter yield (6.48 t ha-1) was obtained from the mixture containing 70% hairy vetch and 30% triticale, and the lowest dry matter yield (2.98 t ha-1) was obtained from the pure triticale sowing (Table 2). In the second year, the highest dry matter yield (6.50 t ha-1) was obtained from the mixture containing 70% common vetch and 30% triticale, and the lowest dry matter yield (2.98 t ha-1) was obtained from the pure triticale sowing (Table 2). According to two year average, the lowest dry matter yield (2.88 t ha-1) was obtained from pure triticale, and the highest (6.23 t ha-1) was obtained from the mixture containing 70% hairy vetch and 30% triticale (Table 2). While these results confirm the findings of Anlarsal and Yağbasanlar[6], Hatipoğlu et al.[19] data are different from findings of some other researchers[14,15,20-22]. These differences might be caused by ecological factors such as precipitation and temperature during the vegetative growth in the experiment. In 2004, the mean dry matter yields of mixtures were higher than yields obtained in 2003 (Table 2). This might be due to higher precipitation in 2004. Mixture yields were higher than pure sowing yields. Similar results have been reported in other studies[17].
Vetch rate in dry matter: The vetch rate in dry matter were significantly different (p<0.01) in both years. There were no differences between the years (Table 2). In the first year, while the highest vetch rate in dry matter was determined from the mixture containing 80% hairy vetch and 20% triticale (78.79%), in the second year, the mixture containing 80% common vetch and 20% triticale the highest (75.68%). The mixture containing 50% common vetch and 50% triticale had the least vetch rate in dry matter in both years (45.79 and 49.14%, respectively). Pisulewska et al.[23] reported that increasing the proportion of legume in mixed (legume-cereal) forages increases the yield of green and dry matter per unit area. These findings have been found higher than findings of Karadağ[24]. These differences might be resulted in ecological factors and the cultivars in the experiment.
Crude protein content: Differences in crude protein content were significant among the pure sowings and mixture sowings (Table 3). For the both experimental years, the lowest crude protein content was obtained from the pure triticale while the highest crude protein content was obtained from the pure common vetch (Table 3). The pure common vetch had the highest crude protein content, averaging 19.08%, while the pure triticale had the lowest crude protein content, averaging 10.39% (Table 3). Haj Ayed et al.[25] reported that the nutritive value at flowering of common vetch was higher than hairy vetch hay’s. This result was similar to our findings. The mean crude protein concentration in 2004 was lower than that in 2003 due to the higher precipitation received (Table 3). Cox and Atkins[26] indicated that more precipitation increased the carbohydrate/protein ratio. In addition, since the crude protein concentrations of legumes are higher than those of cereals the crude protein concentrations of the mixtures increased as the legume rate increased in the mixture[5,16,27,28].
Crude protein yield: The crude protein yields of the pure sowings and mixtures were significantly different (p<0.01) in both years.
| Table 1: | Monthly precipitation, mean temperature and relative humidity in the experimental area |
| Table 2: | Green forage yield and dry matter yield for pure and mixture sowings and vetch rate in dry matter at Samsun in 2003 and 2004. VS: Common vetch VV: Hairy vetch, VP: Hungarian vetch, T: Triticale |
| Means followed by the same letter(s) and columns are not significantly different | |
| Table 3: | Crude protein content and crude protein yield for pure and mixture sowings and land equivalent ratio at Samsun in 2003 and 2004. VS: Common vetch, VV: Hairy vetch, VP: Hungarian vetch, T: Triticale |
| Means followed by the same letter(s) and columns are not significantly different | |
There were no differences between the years (Table 3). Crude protein yield ranged from 0.32 to 1.16 t ha-1 in the first year and from 0.28 to 0.99 t ha-1 in the second year (Table 3). For the average results of two years, the highest protein yield (1.06 t ha-1) was obtained from the 70 hairy vetch + 30% triticale mixture while the lowest protein yield (0.30 t ha-1) was obtained from the pure triticale sowing due to the lower dry matter yield and protein content of triticale (Table 3). These results were different from the findings of some other researchers[14,15,19,20]. Environmental conditions and the cultivars used in the trials could cause such a difference. In addition high total dry matter per area could result in such a difference. In fact, dry matter yields in this trial were higher, resulting in a higher yield than in the above-mentioned experiments. Furthermore, crude protein yields of the mixtures were more productive than those of pure sowings. Present results are in agreement with those of Sobkowicz and Sniady[29].
Land Equivalent Ratio (LER): LER values from the 2 years of the experiments are presented in Table 3. In the data averaged over the 2 years, the highest LER value for dry matter yield (1.76) was obtained from the 50% common vetch and 50% triticale mixture. The mixtures out yielded the pure sowings (LER = 1.45). The LER values was above 1 in both years (respectively, 1.36 and 1.54). Therefore, this means that a mixture uses environmental resources better than pure sowing and competition between mixture components is not high[18,30].
As average of two year, the highest green forage, dry matter and crude protein yield were determined from 70% hairy vetch + 30% triticale mixture. The highest crude protein content was determined from pure common vetch, hairy vetch and hungarian vetch, respectively. It was determined that 80% hairy vetch + 20% triticale mixture had the highest vetch rate in dry matter of mixtures. The mixtures out yielded the pure sowings with respect to dry matter yield (LER=1.45). As result of this study, 70% hairy vetch + 30% triticale mixture in arid seasons, 70% common vetch + 30% triticale in rainfall seasons can be recommended in the similar ecologies because of theirs high forage and crude protein yield.