ASSESSMENT OF YIELD, AGRONOMIC TRAITS AND NUTRITIVE VALUE OF SORGHUM VARIETIES GROWN ON HIGHLY SALINE-ALKALI SOIL

Soil salinity is a crucial abiotic stress severely affecting crops production worldwide. Dual-purpose sorghum (Sorghum bicolor (L.) Moench) is a major source of livestock feed and has great potential for phytoremediation of saline soils. Eight sorghum varieties (N5D61, A60, 4264, 2562, GT2012, F438, 2168 and F968) were evaluated based on their agronomic traits and forage nutritive values as a phytoremediation strategy in a highly saline-alkali soil of the Hetao Irrigation District. Yield, biomass, plant height, stem diameter, leaf number, leaf area as well as crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents varied significantly among varieties at different growth stages. The grain yield of A60 (2.16 Mg ha(-1)) was higher (p<0.05) than that of 4262, 2562, F438, 2168, and F968. The maximum plant biomass was observed in F968 (15.3 Mg ha(-1)) and 2562 (14.9 Mg ha(-1)) varieties compared with other seven varieties at heading and harvest stages, respectively. The CP contents of A60 (6.51%) and N5D61 (4.07%) were higher than other varieties (2.51-3.63%) at the heading stage. The accumulation levels of CP (3.59%) at the heading stage were higher than that (3.25%) at harvest. The variety N5D61 had higher NDF (68.53%) and ADF (37.76%) contents at heading, whereas, at harvest, the response of A60 (NDF, 63.53%; ADF, 35.18%) was best, compared to other varieties. The highest relative forage value (RFV) was observed for Guotian2012 (118.4 and 126.6 at heading and harvest). Ultimately, the production of salt-tolerant crops, such as sorghum, is possible with the use of subsurface pipes in the Hetao Irrigation District.