INTERCROPPING IN A TEMPERATE ENVIRONMENT FOR FORAGE PRODUCTION IN DRYLAND CONDITIONS

İlker Nizam, * Hazım Serkan Tenikecier, Adnan Orak and Alp Kayahan Demirkan. Tekirdag Namık Kemal University, Agricultural Faculty, Field Crops Department, Tekirdag, Turkey. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 6(2), 548-555 549 Mixtures of cool season cereals with legumes are considered good agricultural practice in many countries, (Watson et al., 2002;Knudsen et al., 2004) cultivation of mixtures causing an increase productivity and greater stability of yield (Niggli et al., 2008;Doré et al., 2011). In addition, the risk of lodging of legumes is significantly reduced. Legume mixed crops has a positive effect on soil fertility enriching it with nitrogen through a symbiosis of legumes with Rhizobium bacteria. And due to the huge amount of crop residue left behind (Staniak et al., 2014). Yielding of mixtures and crop quality mostly depends on the selection of genotypes and their participation. Since the arable croplands and ranges in the Trakya Region of Turkey have been diminishing intercropping system may create a better access for increasing forage yield per unit area. In such regions, legume and cereal mixture have shown significant potential for higher forage yield and soil conservation (Anil et al., 1998). In vetchcereal intercropping, cereals provide structural support for vetch growth, improving light absorption and allowing mechanical harvest (Lithourgidis et al., 2006). Common vetch is a popular legume for fresh and dry forage and silage production in Turkey. Hungarian vetch is under increasing demand due to its winter resist and productivity especially in hard winter locations. Narbon vetch had high seed yield is increasing popularity mostly in Trakya Region for animal feeding.
Most researches focused on companion crop mixed growth advantage with that of pure stands. Mariotti et al., (2009) reported that competition had different effects on the different species and that the interaction between above-and below-ground competitions varied among species. Intercropping of barley and vetch was more productive than sole crop of either species (Mohsenabadi et al., 2008). Onal Asci and Egritas (2015) determined that hay and digestible dry matter yield of mixtures were higher than monocrops. Lithourgidis et al., (2007) proposed that the greatest dry matter yield was obtained with wheat and barley sole cropping, whereas the lowest was obtained with the common vetch sole crop. Common vetch intercrops with barley or winter wheat produced higher dry matter than common vetch sole crop. Mean dry matter yield of pure oat was 6,07 t ha -1 and that of pure vetch was 4,14 t ha -1 , with the highest yield (6,32 t ha -1 ) in the oat and vetch mixture (45:55) (Erol et al., 2009). Ullah et al., (2015) stated that oat grown in mixture with vetch showed better forage yield (50,10 t ha -1 ) than oat grown in pure stand (44,34 t ha -1 ). Similarly, barley in combination with vetch resulted in higher forage yield (39,84 t ha -1 ) than barley grown in pure stand (29,20 t ha -1 ). Budaklı Carpıcı and Celik (2014) reported that the highest forage yield (15,21 t ha -1 ) was obtain from % 50 common vetch+% 50 triticale mixture and forage yield of pure stand common vetch was 15,21 t ha -1 . Tuna and Orak (2007) determined that plant height, pod number and branch number of vetch in mixture was 57,8-89,8 cm, 6,3-8,6 and 1,5-2,0, respectively. The researchers reported that fresh forage yield and dry matter yield of common vetchoat mixture was between 15,6-29,0 t ha -1 and 4,8-7,2 t ha -1 . Besides, plant height of oat was between 118,2 cm and 129,0 cm in common vetch-oat mixtures. Ansar et al., (2010) stated that in pure stand, plant height of oat, barley and common vetch were 79,75, 66,94 and 46,30 cm, respectively. The researchers reported that dry matter yield of barley and vetch were 9,64 and 7,71 t ha -1 , respectively. Fresh forage yield of oat, barley and vetch were 59,26 t ha -1 , 41,45 t ha -1 and 25,30 t ha -1 respectively.
The aim of this research was to determine forage potential of vetch (Common vetch, Hungarian vetch and Narbon vetch) and cereals (barley and oat) and their mixtures in dryland conditions of Trakya Region of Turkey.

Material and Methods:-
Site description, climatic and soil conditions:-Experiments were conducted during the 2013-2014 and 2014-2015 growing seasons at the experimental area of Field Crops Department of Agricultural Faculty, Tekirdag Namik Kemal University, Turkey. Experimental area is located at 36° 15´N and 36° 30´ E direction and has a typical Mediterranean climate generally. The meteorological data of the experimental area during growing season from October to July was given at Table 1. It has a long-term rainfall of 477,9 mm during growing season. The total precipitation was 524,2 mm and 598,1mm during the 2013-2014 and 2014-2015 growing seasons, respectively. The average temperature of the first (13,8 °C) and second growing season (13,3 °C) was higher than the long-term average value (12,5°C).
Some important soil characteristics of the experimental area were determined before sowing. The soil had a clayloam texture and moderate lime. Soil test values indicated a pH of 7,06 and 2,37 % CaCO 3 , 77,5 kg ha -1 phosphorus, 887,4 kg ha -1 potassium and 1,16 % organic matter at the depth of 30 cm. 550  Before sowing, 50 kg ha -1 of N and 50 kg ha -1 of P 2 O 5 were applied as a base fertilizer (Using complex fertilizer 20-20-0). The pure sowing rate of common vetch (CV), Hungarian vetch (HV), Narbon vetch (NV), barley (B) and oat (O) were 100, 80, 150, 180, and 180 kg ha -1 , respectively. Sowing was made by hand at row to row distance 25 cm in October of both years at same rate. Sowing rate of a mixture was calculated by multiplying mixture ratio and pure sowing rate of each species. The legume and cereals were seeded in the same rows. The size of each plot was 7,5 m 2 (1,5x5m). The research was carried out in dry conditions. The experiment was conducted in the randomized complete block design with a factorial arrangement; mainly 8 different combinations for 5 different species with three replications.
The harvest stage was determined by taking physiological periods of each species. Vetch species were harvested at lowest pod filling stage of vetch. Harvest time for cereals was % 50 flowering time. Fresh forage yield was recorded from 2,4 m 2 area for each plot and calculated as t ha -1 . 500 g fresh sample was taken from the harvested material, dried at 78 °C for 48 hours and weighed. Dry forage yield was calculated as dry weight percentage. Additionally; plant height, ratio and branch number per plant were determined for the species of harvest time in mixtures. Plant height was recorded in centimeter measured from base to the tip of its main stem. Branch number over main stem per plant was counted.
Analysis of variance of experimental results was calculated according to randomized complete block experimental design with three replications using MSTAT-C statistical software package (MSTAT-C, 1988). Significant differences among the mean values were compared by LSD test (P <0,05) (Duzgunes et al., 1987).

Results of mixtures at common vetch harvest time:-
The yield and yield parameters of pure stand and mixture of common vetch averaged over-two-year data were present in Table 2. Plant height, common vetch ratio, branch number per plant, fresh forage yield and dry forage yield were significantly influenced by the different mixture combination of common vetch (Table 2). Plant height of pure stand and mixture of common vetch was between 81,56-105,06 cm ( Table 2). With regard to different combination of CV, the highest plant height (105,06 cm) and the highest CV ratio (% 61.33) was observed at HV+CV combination; maximum branch number per plant (4,55) was determined from B+CV mixture. Fresh forage production is the important character for forage crops. Fresh forage yield was found between 26,21(t ha -1 ) and 36,52(t ha -1 ). Also, dry forage yield was recorded between 6,03(t ha -1 ) and 9,17 (t ha -1 ). The highest fresh forage yield (36,52 t ha -1 ) and dry forage yield

Results of mixtures at Hungarian vetch harvest time:-
The yield and yield parameters of pure stand and mixture of Hungarian vetch averaged over-two-year data were present in Table 3. Significant differences were found among the different mixture combination of Hungarian vetch for plant height, Hungarian vetch ratio, branch number per plant, fresh forage yield and dry forage yield (Table 3).  (Table 3). With regard to different combination of HV, the highest plant height (112,67 cm) was observed from sole crop HV sowing, the highest HV ratio (% 45,33) was observed at NV+HV combination. Minimum and maximum branch number of HV was found to be 2,77 and 4,85 respectively. Maximum branch number (4,85) was determined from B+HV mixture. Fresh forage yield was between 27,99-49,53 t ha -1 and dry forage yield was between 8,06-12,04 t ha -1 . Maximum fresh forage yield (49,53 t ha -1 ) was obtained from B+HV combination; the highest dry forage yield (12,04 t ha -1 ) was obtained B+HV combination.  reported that fresh forage yields of HV genotypes were 11951,91 -14902,71 kg ha -1 and dry matter yields of HV genotypes were 2884,69-3378,89 kg ha -1 . Orak and Nizam (2012) determined that fresh and dry forage yield of pure stand Hungarian vetch were 2474,45 and 516,76 kg da -1 , respectively. Additionally, fresh forage yield of Hungarian vetch mixtures with other vetch and barley were determined between 2386,95 and 4031,39 kg da -1 dry forage yield changed between 706,08 and 1082,63 kg da -1 , respectively. These results are lower from our findings. Differences may originate from location and mixture combination.

Results of mixtures at Narbon vetch harvest time:-
Narbon vetch is the native crop of Trakya Region generally using for cattle feeding. The yield and yield parameters of pure stand and mixture of Narbon vetch averaged over-two years data were present in Table 4. Plant height, Narbon vetch ratio, branch number per plant, fresh and dry forage yield were significantly influenced by the different mixture combination of Narbon vetch (Table 4). Plant height of NV changed between 83,17 cm and 128,00 cm (Table 4). Maximum plant height (128.00 cm) was determined from pure stand Narbon vetch sowing. Orak and Nizam (2009) and Nizam et al., (2011 a) findings were reported that plant heights of NV genotypes were change between 43,00 cm and 102,28 cm in addition 43,02 cm and 78,85 cm, respectively. Our findings for plant height of NV are accordance with Orak and Nizam (2009) and . NV ratio was found highest (61,50 %) on O+NV mixture than the other combinations. Branch number per plant of NV was between 1,62-2,83. Maximum branch number per plant (2,83) was determined from sole NV plots. Similar results have been obtained by  that branch number of NV was changed between 1,40 and -3,17. Fresh forage yield and dry forage yield were between 2564,00-3988,33 kg da -1 and 902,50-1105,50 kg da -1 , respectively. In addition, the highest fresh forage yield (3988,33 kg da -1 ) was determined from O+NV combination, maximum dry forage yield (1105,50 kg da -1 ) was determined from O+NV combination. Our finding was relatively similar to Orak and Nizam (2012). The researcher reported that fresh and dry forage yield of pure stand Narbon vetch were 2826,86 and 501,52 kg da -1 , respectively. Additionally, fresh and dry forage yield of Narbon vetch mixtures with other vetch and barley were determined between 3293,71-3940,19 kg da -1 and 739,05-768,59 kg da -1 , respectively. Our results were found to be higher from previous studies. It can be caused by mixture combination, climate and soil conditions.

Results of mixtures at barley vetch harvest time:-
The vetch ratio in the mixtures can arise quality of harvested herbage. Barley is very important forage greens. Additionally, cereals are known intercropping of grows with legume provides structural support of climbing vetches and improves light interception. The yield and yield parameters of pure stand and mixture of barley averaged over 553 two-year data were present in Table 5. Significant differences were found among the different mixture combination of barley for plant height, barley ratio, fresh forage yield and dry forage yield (Table 5).

Results of mixtures at oat harvest time:-
The yield and yield parameters of pure stand and mixture of oat averaged over-two years data were present in Table  6. Plant height, oat ratio, fresh forage yield and dry forage yield were significantly influenced by the different mixture combination of oat (Table 6). Lowest and highest plant height of oat was found to be 75,68 cm and 103,29 cm (Table 6). Among the different mixture ratio of oat with the other legume and cereal; the highest plant height of oat (103,29 cm) was obtained from CV+HV+O mixture; the highest ratio of oat (73,67 %) was observed from HV+O combination. Fresh forage yield was between 24,51-37,42 t ha -1 . Also, dry forage yield was between 6,01-9,50 t ha -1 . Maximum fresh forage yield (37,42 t ha -1 ) and dry forage yield (9,50 t ha -1 ) were obtained from NV+O combination. The results are in line with the findings of Tuna and Orak (2007), Ullah et al., (2015) and Erol et al., (2009). Some results differ with the findings of Tuna and Orak (2007), who reported the highest plant height in pure stand.