Spatial heterogeneity in the properties of hydroponic wheat fodder and its sustainability

This study was conducted to determine the heterogeneity of the quantitative and qualitative properties of fodder growth in cultivated hydroponic wheat fodder (HWF) in the growth tray area and to evaluate the impact on the environment. HWF was grown using nutrient film technique. Yield productivity (YP) of HWF in the growth tray area was divided into four characteristic zones (A, B, C, and D). The most fertile zone A accounted for only 22.3 ± 4.2% of the entire growth tray area, while zone B accounted for 44.7 ± 4.0%. Zones C and D, which accounted for 28.0 ± 1.3% and 5.0 ± 0.3% area, respectively, pose various problems for forage production, i.e., they negatively impact the quantity and quality of HWF, as well as the environment. If all areas in the growth tray support the highest fodder YP (zones A and B), then one kg of dry wheat grains will yield about 6–7 kg of HWF (consisting of 10.7–12.4% dry matter, 17.3–17.5% crude protein, 1.8–2.3% starch, 13.1–14.4% crude fiber, and 4.5–4.6% ether extract). Results of life cycle assessment show that HWF with YPs of 3–5 kg from one kg of dry grains (zones C and D) has the most adverse impact on the environment (150 and 220 kg CO 2eq t −1 ). Under optimum conditions (zone A), CO 2eq varied from 94 to 115 kg CO 2eq t −1 of feed. Environmentally, HWF production had the most impact on marine aquatic ecotoxicity, abiotic depletion, global warming potential, and freshwater aquatic ecotoxicity.