The paper presents the preparation and use of pressed solid biofuel of multi-crop plants (fibrous hemp (Cannabis sativa L.), maize (Zea mays L.) and faba bean (Vicia faba L.)) as mono, binary and trinomial crops. The results of the investigation show that three main chemical elements (carbon, oxygen and hydrogen) accounted for 93.1 to 94.9% of the biomass pellet content. The moisture content varied from 3.9 to 8.8%, ash content from 4.5 to 6.8% and calorific value from 16.8 to 17.1 MJ·kg−1. It was found that the density (DM) of all variants of pellets was very similar; the faba bean biomass pellets had the highest density of 1195.8 kg·m−3 DM. The initial ash deformation temperature (DT) of burning biomass pellets was detected, which varied from 976 to 1322 °C. High potassium (K), calcium (Ca) and phosphorus (P) concentrations were found in all types of biomass ash. The quantities of heavy metals in pellet ash were not large and did not exceed the permissible values according to Lithuanian legislation. These chemical properties of multi-crop biomass ash allow them to be used in agriculture for plant fertilization.
Agriculture uses a lot of fuel, fertilizers, pesticides and other substances, while emitting large amounts of GHGs. It is important to optimize these inputs and outputs. One such way is by increasing crop biodiversity. For this reason, single crops and mixtures of maize, hemp and faba bean as binary and ternary crops were investigated at the Experimental Station of Vytautas Magnus University, Lithuania. The results showed that consumption of diesel fuel was 31–46% higher than in single and 22–35% higher than in binary cultivations was found in a ternary crop. This had influence on the highest energy input of near twice higher than in maize and hemp single crops and maize+hemp binary crop, but similar with binary crops with faba bean. Despite this, the productivity of the ternary crop and, at the same time, the energy output were 2–5 times higher than in other treatments. This compensated for higher energy inputs and the energy efficiency ratio. In the ternary crop, energy productivity was from 1.1 to 2.8 times higher and net energy was 1.9–5.3 times higher than in other tested cultivations. The highest total GHG emissions were obtained in binary maize+hemp and maize+faba bean cultivations (1729.84 and 2067.33 CO2eq ha−1). Ternary cultivation with the highest energy inputs initiated average GHG emissions of 1541.90 kg ha−1 CO2eq. For higher efficiency, the ternary crop could be sown and harvested in one machine pass. Faba beans should be included in ternary crops, as their biomass makes up a significant part of the total biomass produced. We recommend reviewing the intercropped faba bean seeding rates, as faba bean seeds have a high energy input equivalent.
Growing as much crop biomass as possible in the shortest possible time is the target for most bio-energy producers. However, according to the requirements of the Green Deal, the consumption of fertilizers and crop protection products will have to be significantly reduced between 2023 and 2027. In order to meet all the necessary conditions for the production of biomass, a stationary field experiment was carried out at the Experimental Station of Vytautas Magnus University, Lithuania, in 2020–2021. Multi-cultivations of maize, hemp and faba bean were investigated. The aim of this study was to ascertain the impact of multi-cropping intensity on soil structural composition, stability, penetration resistance and gas concentration–respiration. As expected, multi-cropping stabilized the gas concentration and emission from the soil and decreased the proportion of micro-structures in the top soil layers. However, the stability of the soil decreased in all the experimental plots. Gas concentration and respiration mainly depended on soil structural composition, temperature and moisture content. The results of the experiment suggest performing investigations at a long-term scale because the intensive variation of meteorological conditions had a higher impact on the soil properties than the multi-cropping systems.
Multi-cropping is becoming an increasingly popular technique in agriculture to tackle major and complex agroecosystem problems such as biodiversity and soil fertility loss, erosion and degradation, increased greenhouse gas emissions, etc. Comprehensively assessing the impact of multi-cropping intensity on agroecosystems is a new and still under-researched approach that can provide a better understanding of the impact of individual indicators on the overall functioning of biodiverse agroecosystems. Data from a stationary field experiment using multi-cropping at the Vytautas Magnus University Experimental Station between 2020 and 2022 were used to carry out this study. The study included maize, hemp, and faba bean as single, binary, and ternary crops. A complex assessment approach (CEI value) was used to determine the impact of these crops on the agroecosystem, the interrelationships between the main indicators, and the strength of their effects. It was found that the ternary maize–hemp–faba bean crop had the most positive effect on the agroecosystem. The effectiveness of other crops was 2 to 35% less. The lowest value was calculated for the maize–faba bean crop.
Agriculture uses a lot of fuel, fertilizers, pesticides and other substances, while emitting large amounts of GHGs. It is important to optimize these inputs and outputs. One such way is increas-ing crop biodiversity. For this reason, single crops and mixtures of maize, hemp and faba bean as binary and ternary crops were investigated at the Experimental Station of Vytautas Magnus Uni-versity, Lithuania. Results showed that consumption of diesel fuel was by the 31-46% higher than in single and 22-35% higher than in binary cultivations was found in a ternary crop. This influenced on the highest energy input or near twice higher than in maize and hemp single crops and maize+hemp binary crop, but similar with binary crops with faba bean. Despite this, the productivity of the trinary crop and, at the same time, the energy output were 2-5 times higher than in other treat-ments. This compensated for higher energy inputs and the energy efficiency ratio. In ternary crop, energy productivity was from 1.1 to 2.8 times higher and net energy was by 1.9-5.3 times higher than in other tested cultivations. The highest total GHG emissions were obtained in binary maize+hemp and maize+faba bean cultivations (1729.84 and 2067.33 CO2eq ha-1). Ternary cultiva-tion with the highest energy inputs initiated average GHG emission - 1541.90 kg ha-1 CO2eq. For higher efficiency, ternary crop could be sown and harvested in one machine pass. Faba beans should be included in the ter-nary crops, as their biomass takes a significant part of the total biomass produced. We recommend to review the inter-cropped faba bean seeding rates as faba bean seeds have a high energy input equivalent.
As the population grows, more food is needed to keep the food supply chain running smoothly. For many years, intensive farming systems have been used to meet this need. Currently, due to intense climate change and other global natural problems, there is a shift towards sustainable use of natural resources and simplified methods of tillage. Soil tillage intensity influences the distribution of nutrients, and soil’s physical and mechanical properties, as well as gas flows. The impact of reduced tillage on these indices in spring barley cultivation is still insufficient and requires more analysis on a global scale. This study was carried out at Vytautas Magnus University, Agriculture Academy (Lithuania) in 2022–2023. The aim of the investigation was to determine the effect of the tillage systems on the soil temperature, moisture content, CO2 respiration and concentration in spring barley cultivation. Based on a long-term tillage experiment, five tillage systems were tested: deep and shallow moldboard ploughing, deep cultivation-chiseling, shallow cultivation-chiseling, and no tillage Shallow plowing technology has been found to better conserve soil moisture and maintain higher temperatures in most cases. During almost the entire study period, the spring barley crop with deep cultivation had lower moisture content and lower soil temperature. Shallow cultivation fields in most cases increased CO2 emissions and CO2 concentration. When applying direct sowing to the uncultivated soil (10–20 cm), the concentration of CO2 decreased from 0.01 to 0.148 percent. pcs. The results show that in direct sowing fields, most cases had a positive effect on crop density. Direct sowing fields resulted in significantly lower, from 7.9 to 26.5%, grain yields of spring barley in the years studied.