Hay yield and nitrogen harvest in smooth bromegrass mixtures with alfalfa and red clover in relation to nitrogen application

• Published in: European journal of agronomy 1999-03, Vol.10 (2), p.145-151
• Main Authors: Gökkuş, A., Koç, A., Serın, Y., Çomakli, B., Tan, M., Kantar, F.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Alfalfa; AZOTE; Biological and medical sciences; BROMUS INERMIS; CROP RESIDUES; CROP YIELD; Cropping systems. Cultivation. Soil tillage; CULTIVO MIXTO; CULTURE EN MELANGE; FOIN; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Cropping systems and patterns; HAY; Hay yield; HENO; MEDICAGO SATIVA; MIXED CROPPING; Mixtures; NITROGEN; Nitrogen fertilization; Nitrogen harvest; Nitrogen, phosphorus, potassium fertilizations; NITROGENO; Red clover; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; RESIDU DE RECOLTE; RESIDUOS DE COSECHAS; Smooth bromegrass; Soil-plant relationships. Soil fertility. Fertilization. Amendments; TRIFOLIUM PRATENSE; TURKEY; TURQUIA; TURQUIE
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/S1161-0301(98)00061-6

An experiment was conducted in order to investigate hay yield and nitrogen harvest in binary smooth bromegrass ( Bromus inermis Leyss cv. Tohum Islah) mixtures with alfalfa ( Medicago sativa L. cv. Kayseri) and red clover (Trifolium pratense L. cv. Tohum Islah) in Erzurum, Turkey for 5 years between 1991 and 1995. The Hay yield, nitrogen harvest, protein concentration and land equivalent ratio (LER) in the mixtures with alternating rows of 1:1, 2:1 and 1:2 of smooth bromegrass with alfalfa and red clover were compared to those in pure legume stands without any N-fertilizer application or pure smooth bromegrass stands that received 0, 50, 100 and 150 kg ha −1 N. The mixtures had no N fertilization apart from 40 kg N ha −1 in the establishment year. The dry matter production in all the mixtures receiving no N fertilizer application was higher than in pure legume stands. Pure grass stands were sustained only with the application of 150 kg ha −1 N. The highest hay yields were obtained from the mixtures of smooth bromegrass (Sb) with red clover (Rc) (2Rc 1Sb) (14.65 t ha −1) and with alfalfa (A) (1A 1 Sb) (14.49 t ha −1). Although N application increased Sb yields in pure stands, the highest yields obtained with N fertilization were still lower than the yields in the mixtures without N application. The superiority of the mixtures was also reflected by their large N harvests (e.g. 355.9 kg N ha −1 in 2Rc 1Sb plots) compared to pure Rc (317.8 kg N ha −1), pure A (294.3 kg N ha −1) and pure Sb stands that received 150 kg N ha −1. The nitrogen harvest increased in pure Sb plots as the N doses applied increased. Furthermore, the protein concentration of the hay from the mixtures (158.2–165.7 mg g −1) was equal to that of the pure A stands (165.7 mg g −1) and higher than that of pure Sb stands (122.9 mg g −1 at 150 kg N ha −1 application) although the hay from pure Rc plots had the highest protein concentration (179.3 mg g −1). The LER values were also higher in the mixtures (e.g. 1.28 in 1A 1Sb and 1.28 in 2Rc 1Sb plots) compared with the pure stands. The mixture plots also had a more balanced temporal distribution of hay. The grass component was more productive in early spring, whereas the legume fractions grew better in the summer. In conclusion, for a sustainable production of high-quality hay and greater N harvests without using N fertilizers, binary mixtures of Sb with A in alternating rows (1A 1Sb) were recommended for long-purpose stands and in alternation wi