In traditional farming, plants require a lot of space (growing area), they consume a large amount of water, absorb a small percentage of nutrients in soil and are completely dependent on meteorological conditions. Therefore, growing crops in this way entails high costs and a high risk of invested funds. One of the measures to reduce these factors is the use of hydroponics. In the study six types of hydroponic systems (HS) plant constructions based on plant nutrient supply technology were reviewed: ebb and flow HS; nutrient film technique (NFT) HS; aeroponics; deep water culture HS; "wick" HS and drip-irrigation HS. In addition, a review of the structural design of the hydroponic systems identified their advantages and disadvantages in green fodder production. The most promising technology for the cultivation of green fodder is the NFT HS. This cultivation technology is appreciated in feed production for its highly utilized growing room volume and closed-loop irrigation solution to plants, which allows it to be easily automated based on solution parameters. Seven farms already have this technology in place in Lithuania. In order to optimize hydroponic fodder cultivation technology, it is expedient to improve NFT equipment and process control systems.

Application of hydroponic systems in feed production has not been extensively studied. Therefore, there is insufficient data on the effect of the slope of hydroponic growing trays used in the nutrient film technique on wheat fodder yield and its qualitative parameters. The slope of the trays has only been studied for food crops. This study conducted experimental research using a nutrient film technique hydroponic fodder growing device to evaluate the impact of growing tray slope angle on hydroponic wheat fodder production. The slope angle of the growing trays was changed from 2.0% (1.15°) to 8.0% (4.57°) with increments of 1.5% (0.86°). This research used two different light sources for wheat sprout illumination: indoor lighting (fluorescent lamps) and light-emitting diode illumination. In addition, two nutrient solutions were used for sprout irrigation: tap water and a solution enriched with macro- and microelements. Experimental studies confirmed the hypothesis that the slope angle of growing trays significantly affects the yield of wheat fodder grown for seven days. Analyzing the results, we found that the highest yield of wheat fodder after seven days of cultivation was achieved with growing trays sloped by 6.5% and using indoor lighting. In addition, we achieved the highest wheat fodder dry matter content using a 6.5% slope angle. Experimental studies also confirmed the hypothesis that using macro- and micronutrients in the nutrient solution does not significantly affect the yield of wheat fodder grown hydroponically for seven days.

Harvesting of high-moisture corn ears poses a challenge due to the high level of grain damage. In the present study, a series of concaves adapted to moist corn ears threshing was developed and evaluated. The key improvements include a concave arc shape and oblique crossbars to reduce corn grain damage and threshing losses. Results show that the geometrical shape of the concave arc and its crossbars have a significant influence on the grain detachment from the ears, grain separation through the concave, and grain damage during the threshing process of moist ears of corn. Studies show that replacing the concave rounded crossbars with oblique ones can increase threshing performance of moist corn ears. A concave with an Archimedes’ spiral arc and oblique concave crossbars is an effective approach to improve corn grain quality and reduce harvest losses due to grain damage. We identify the optimal design for threshing corn ears as an experimental concave with an Archimedes’ spiral arc of 8 mm height, with 19 mm wide crossbars of the concave with an oblique working plane (tilt angle 25°). This design achieves minimal threshing grain losses (0.03%) when threshing moist ears (grain moisture content ~35%), and damaged grain in the threshing apparatus does not exceed the permissible limit of 3% at an ear feed rate of 16.8 kg s−1.

Agriculture uses more water than any other resource to produce animal feed and wastes much of it through inefficiency. One possible alternative to solve this problem is hydroponically grown animal fodder, which under hydroponic conditions can achieve optimal results and, most importantly, use expensive resources, such as water, more efficiently. In the conducted research, different irrigation scenarios (IR1–IR6) were investigated when the water flow rate, irrigation frequency, and duration (IR1—1 l min−1, 4 times day−1, 120 s; IR2—2 l min−1, 4 times day−1, 120 s; IR3—3 l min−1, 4 times day−1, 120 s; IR4—1 l min−1, 8 times day−1, 60 s; IR5—2 l min−1, 8 times day−1, 60 s; and IR6—3 l min−1, 8 times day−1, 60 s;) were changed during the hydroponic wheat fodder cultivation using a 7-day growth cycle. The results showed that the highest yield from the used seed was obtained in scenarios IR5 (5.95 ± 0.14 kg kg−1) and IR6 (5.91 ± 0.19 kg kg−1). In terms of frequency and irrigation duration, in IR1, IR2, and IR3, the average yield reached 4.7 ± 1.85 kg kg−1, and in scenarios IR4, IR5, and IR6, the average yield was 15.4% higher—5.55 ± 1.63 kg kg−1. The results obtained showed that by increasing the flow rate (from 1 l min−1 to 3 l min−1) and the frequency of irrigation (from 4 times day−1 to 8 times day−1), the yield increased by 32.5%, but the mass of the grown fodder per liter of water used simultaneously decreased by 50.6%. The life cycle assessment showed that although irrigation scenario IR4 had the most efficient use of water, the CO2 footprint per functional unit (FU) was the highest due to the lowest yield compared to the other five irrigation scenarios. The lowest environmental impacts per FU were obtained in scenarios IR5 and IR6 (100.5 ± 3.3 and 100.6 ± 2.4 kg CO2eq t−1, respectively).