Agrivoltaic systems provide a promising solution for mitigating the competition for land between food and energy production. This study examines the performance of an agrivoltaic system in southern ...Spain, which integrates bifacial PV technology with three different olive cultivars. Different configurations of clearance height and PV modules tilt are analyzed. The findings indicate that PV modules tilted near the site's latitude achieve the highest energy yield, while vertically-oriented modules lead to the greatest olive yield. The variation in tilt angle has a more significant impact on PV yield, whereas the height of the PV modules primarily affects olive tree yield. To quantify the combined land productivity of energy and crop outputs, the land equivalent ratio (LER) is employed. The results demonstrated a maximum LER of 171% when modules are tilted at 20°, thereby enhancing overall land productivity. Moreover, the study reveals that olive trees display a moderate sensitivity to shading. These findings underscore the importance of optimizing the configuration of PV systems for dual land use in agrivoltaic while taking agricultural productivity into account.
•An agrivoltaic system of bifacial PV and three varieties of olive trees were studied.•The raytracing approach and olive light response were used to model the tree yield.•The influences of photovoltaic module height and tilt were quantified.•The peak land equivalent ratio (LER) of 71% resulted when PV panels were tilted at 20°.•The study revealed that olive trees displayed moderate sensitivity to shading.
•Greater RUE and LER were found in RI and S32 in common vetch-oat intercropping.•Intercropping improved RUE by 27 % than the value expected from the monocultures.•Using the border row effect is a key ...to increase yield in strip intercropping.
Common vetch (Vicia sativa L.)-oat (Avena sativa L.) intercropping is widely used for forage production, especially in alpine regions. To understand the effects of row configuration on radiation interception and productivity in common vetch-oat strip intercropping under low-input conditions, a field experiment with seven treatments of different numbers of rows for common vetch and oat 1:1 (RI), 2:1 (S21), 3:1 (S31), 3:2 (S32), 4:2 (S42), 4:3 (S43), and 5:3 (S53) and sole cropping treatments were conducted in the eastern Qinghai-Tibetan plateau (QTP) during 2016 and 2017. Compared with sole cropping, intercropping significantly increased plant height but decreased the net photosynthetic rate (Pn) and the fraction of intercepted photosynthetically active radiation (ƒIPAR) of common vetch in the configurations with narrow strip width such as RI, S21, S31, and S32; as the common vetch strip width increased, their performance tended to be similar with common vetch sole cropping. Plant height, Pn, and ƒIPAR were significantly greater for intercropped oat than oat sole cropping, but decreased as the width of the oat strip increased. On average, intercropping systems improved radiation use efficiency (RUE) by 27 % in comparison to the value expected from the monocultures. The land equivalent ratio (LER) was 1.20 (flowering stage) and 1.14 (maturity stage) on average, and greater than one in all intercropping treatments. Moreover, oat yield in border rows was significantly higher by 41–52 % compared with inner rows, indicating that the border row effect of the dominate crop is a key to increasing yield in common vetch-oat strip intercropping. In order to maximize the utilization of the border row effect, one row or two rows of oat strip which can mitigate intraspecific competition is recommended under low-input conditions. The optimal row configurations RI and S32, which achieved the highest RUE (2.9–3.4 g MJ−1), LER (1.16–1.27), yield (1257−1502 g m-2), and monetary advantage index, can be applied in common vetch-oat strip intercropping for sustainable forage production in alpine regions.
•Rice-water spinach intercropping effectively control rice sheath blight and leaf folders.•Rice-water spinach intercropping has advantage of rice yield and land use efficiency.•Rice-water spinach ...intercropping increased Si concentration and absorption in rice leaves.
Intercropping is an effective agricultural practice for crop production, resource utilization, and pest control. However, aquatic crops (e.g., rice) intercropping is relatively rare. Field experiments of two years/four seasons (early and late seasons in 2012, 2013) was carried out to test the effects of rice-water spinach intercropping on yield, disease and pest control, and Si, N nutrition of rice plant in the present study. The experiment contained three treatments including rice monoculture, water spinach monoculture and rice-water spinach intercropping with three replicates by randomized block design. Results showed that rice-water spinach intercropping significantly reduced the incidence of disease and pest of rice, with a reduction of rice sheath blight by 17.3%–50.6% and rice leaf folders by 5.1%–58.2%. For yield, intercropping resulted in an increase of rice yield by 45.1%–71.7% in early season and 20.9%–34.3% in late season, but a decrease of water spinach yield by 14.1%–37.1% in early season and 3.8%–18.3% in late season. However, rice-water spinach intercropping gave a higher land equivalent ratio (1.02–1.17) therefore improved land utilization efficiency. Furthermore, intercropping significantly increased Si concentration, Si and N absorption in rice leaves in ripening stage compared with rice monoculture. Our findings suggest that rice-water spinach intercropping exhibits yield advantage for rice or total yield, improves Si nutrition of rice and provides an environmentally sound approach in controlling disease and pest.
Global demand for food continues to grow as a result of rising incomes and population growth. Meanwhile, the sustainability of food production is affected by climate change and agricultural soil ...degradation.
The objective of this study was to evaluate the dynamic changes of maize/soybean yield, yield stability and soil fertility under mono-cropping and intercropping systems with different nitrogen application rates.
The yield stability and sustainability of maize and soybeans were studied from 2017 to 2020 (Northeast Agricultural University, Acheng Experimental Site) according to the changes in crop yield, actual yield loss index, soil fertility over time as well as the differences in coefficient of variation and sustainable yield index under different cropping patterns in the maize/soybean intercropping system. This study established three cropping patterns (maize monoculture, soybean monoculture, and maize/soybean intercropping) with four nitrogen application rates (0/0 kg N ha–1, N0; 180/40 kg N ha–1, N1; 240/80 kg N ha–1, N2; 300/120 kg N ha–1, N3) based on the two-factor split block design.
The maize and system yield indicated that intercropping was superior to the corresponding monoculture throughout the four-year experiment. With the extension of planting season, the yield from intercropping with nitrogen treatment (N1, N2 and N3) was higher than that without nitrogen treatment (N0). The yield stability of the intercropping system was also higher than that of the matched monoculture system. The coefficient of variation of the intercropping system was 18.83 % on average, which was lower than that of the matched monoculture system. In four years, the average contribution rate of soil fertility in intercropping treatment was higher than that in monoculture treatment. The structural equation model results suggested that the effect of nitrogen application rate on yield and yield stability was greater than that of cropping pattern.
The yield and yield stability of maize/soybean intercropping over time was higher than matched monoculture under different nitrogen application rates due to higher soil fertility contribution in intercropping.
This study provides theoretical evidence for maintaining the sustainability of legume and cereal intercropping and improving food security in the increasingly intensive global cropping systems.
•Maize/soybean intercropping over time improved stability of crop yields.•Soil fertility contribution rate in intercropping was higher compared to monoculture.•Contribution rate of N fertilizer to maize yield stability was greater than soybean.•Influence of fertilizer on yield stability was greater than that of cropping pattern.
Display omitted
•Higher soil bacterial diversity was found in rotational strip intercropping (RMP).•Soil carbon sequestration increased by 6.22%6.22 %∼11.88 % in 0−40 cm soil layer of RMP.•RMP ...reduced soil erosion 8.28 %∼45.45 % and resulting carbon emission 22.73 %∼45.16 %.•Higher crop yields and economic benefits can be achieved in RMP.•The 4-year average land equivalent ratio of RMP was 1.20.
The northern agropastoral ecotone region is an extremely vulnerable but vitally important ecological region in China. However, the synergistic agricultural production mode of economy and ecology is still rare in this region. In this study, a 4-year fixed-point experiment was conducted to study the soil characteristics, production and ecological effects of three typical planting modes (continuous maize CM, continuous peanuts CP and a rotational strip intercropping of maize and peanuts RMP). The results indicated that RMP had multiple benefits compared with CM and CP: it improved the soil carbon stocks in the 10−20 cm soil layer by 20.11 % and 34.19 %, respectively; it increased the grain yield and economic benefits, with an increase of 19.68 % and 17.29 % in the average annual yield of maize and peanuts, respectively, and an increase in revenue of 23.14 % and 13.99 %, respectively; the land use efficiency can be improved and the average land equivalent ratio of 4 years is 1.20; the soil erosion and the resulting carbon emissions were reduced, with a decrease in the intensity of erosion of 8.28 % and 45.45 %, respectively, and a decrease of 22.73 % and 45.16 % in the resulting carbon emissions, respectively. Correlation analysis showed that the improvement in soil characteristics, such as the modification of soil organic carbon, mineralized carbon, and an increase in available nutrients, helps to increase the yields of maize and peanut in the RMP. In conclusion, RMP resulted in multiple benefits and was more consistent with sustainable agricultural production in the agropastoral ecotone region.
•Higher pea N2-fixation in mixtures led to higher protein concentration and yield.•Oats with high Δ values forced the companion peas to fix more N2.•Δ values of oats in mixed stands were positively ...correlated to yield and quality.•Peas in mixed stands with lower Δ values resulted in higher yield and quality.
Three oat (Avena spp.) and three field pea Pisum sativum subsp. arvense (L.) Asch. cultivars were grown in pure stands and interspecific, binary mixtures under Mediterranean conditions for two growing seasons (2011–12 and 2012–13). The aim of the work was to identify traits contributing to the complementary use of soil nitrogen (N) and water in intercrops. Such traits could be used as putative selection criteria for cultivars well-adapted to intercropping systems. The 15N natural abundance method was used to assess the percentage of N derived from N2-fixation (%Ndfa) in pure stands and intercrops and the percentage of N transferred from pea to oat (%Ntrans) in intercrops. Carbon isotope discrimination (Δpea, Δoat) was used as an assessment of water use efficiency. Isotope determinations were conducted when 30% of pea flowers were open. Dry matter yield (DM) of pure stands and intercrops was estimated at forage silage maturity of peas, and forage quality traits (protein, fat, ash, crude fiber, and nitrogen free extracts concentrations) were measured. Intercropping either increased or decreased %Ndfa depending on the cultivars included in the mixtures. High %Ndfa by pea in mixtures was associated with a high contribution of pea in the mixture and high crude protein concentration in DM. High amounts of fixed N and N accumulated in pea were necessary to maximize protein concentration and protein yield in intercrops. These amounts were calculated to be 72.0 and 94.4 kg N ha−1 for protein concentration and 124.2 and 160.8 kg N ha−1 for protein yield. Oats in intercrops seemed to affect the N niche of peas. Δoat values were positively correlated with %Ndfa, the amount of fixed N in pea and the amount of N accumulated in pea. A plausible explanation for this is that high Δoat values were indicative of a better access to soil water and nitrate (NO3-N) sources through a deeper and denser rooting system, thus increasing the competition on the companion pea which led to higher percentage of N2-fixation and consequently to higher amounts of N fixed by and accumulated in pea. High-Δ oats were less dependent on N transferred from pea as was indicated by a negative correlation between these two traits. As a consequence, high Δoat values were associated with high protein concentration and protein yield. In contrast, Δpea values were negatively correlated with protein concentration and protein yield. Peas, having a less competitive rooting system compared to oats, were adaptive to intercropping when they had a more conservative use of soil water (lower Δpea), and thus avoided competition. Land equivalent ratios for dry matter yield (LERDM) and protein yield (LERCPY) were affected by growing seasons. LERDM was <1.00 (0.88) in 2012-13 growing season indicating that intercropping was not favored. This season was characterized by lack of precipitation during December 2012 and January 2013, high precipitation in February (>62% of season’s water input) and mild temperatures during winter (November to February). The very early, moderately tall oat cultivar Flega had the highest LER values, regardless of the companion pea cultivar. This was an indication that Flega was favored by growing in intercrops, however, Flega’s mixtures were not among the high-yielding mixtures.
•A novel method to assess the distance of influence of agroforestry trees on crops.•Combining maps of spectral indices (Unmanned Aerial Vehicle) and geostatistics.•Geostatistical distance of ...influence of Faidherbia on millet was 17 m.•Crop-partial Land Equivalent Ratio computed (1.16), without need of true sole crops.•Yield (0.73 t ha−1) upscaled from sample plots to whole plot (error <20 %).
The trees in agroforestry plots create spatial heterogeneity of high interest for adaptation, mitigation, and the provision of ecosystem services. But to what distance, exactly, from the tree? We tested a novel approach, based upon geostatistics and Unmanned Aerial Vehicle (UAV) sensing, to infer the distance at which a single agroforestry tree affects the surrounding under-crop, to map yield, litter (i.e. stover) and compute crop-partial Land Equivalent Ratio (LERcp) at the whole-plot level.
In an agro-silvo-pastoral parkland of semi-arid western Africa dominated by the multi-purpose tree Faidherbia albida, we harvested the pearl-millet under-crop at the whole-plot scale (ca. 1 ha) and also in subplot transects, at three distances from the trunks. We observed that the yield was three times higher below the tree crown (135.6 g m−2) than at a distance of five tree-crown radii from the trunk (47.7 g m−2). Through geostatistical analysis of multi-spectral, centimetric-resolution images obtained from an UAV overflight of the entire plot, we determined that the ‘Range’ parameter of the semi-variogram (assumed to be the distance of influence of the trees on the Normalized difference vegetation index (NDVI)) was 17 m. We correlated the yield (r2 = 0.41; RRMSE = 48 %) and litter production (r2 = 0.46; RRMSE = 35 %) in subplots with NDVI, and generated yield and litter maps at the whole-plot scale. The measured whole-plot yield (0.73 t ha-1) differed from the one estimated via the UAV mapping by only 20 %, thereby validating the overall approach. The litter was estimated similarly at 1.05 tC ha-1 yr-1 and mapped. Using a geostatistical proxy for the sole crop, LERcp was estimated 1.16, despite the low tree density.
This new method to handle heterogeneity in agroforestry systems is a first application. We also propose strategies for extension to the landscape level.
IntroductionThe agricultural systems are facing numerous challenges in maintaining and providing food security. Achieving this goal, considering the growing global population is possible through the ...application of sustainable agricultural principles to increase crop yield and reduce environmental costs. The widespread use of chemical inputs, particularly nitrogen fertilizers, by farmers globally to enhance yields has resulted in numerous environmental hazards, including soil and groundwater pollution. Intercropping systems emerge as a viable strategy to augment yield, curtail reliance on chemical fertilizers, and safeguard the environment. Enhancing the yield and quality of forage has become a paramount concern in the agricultural sector in recent times. Various approaches exist to achieve this objective, among which intercropping cereals and legumes stands out as a promising solution. One of the most sustainable farming methods in saline and arid lands is drying livestock products using salt-tolerant plants, which can also be beneficial for farmers.Materials and MethodsThis experiment was conducted at the Agricultural Research Institute of Zabol University using a randomized complete block design with three replications. The experimental treatments include different patterns of intercropping kochia and cowpea, namely: 100% Kochia (K100), 50% kochia: 50% cowpea (K50:C50), 75% kochia: 25% cowpea (K75:C25), 25% kochia: 75% cowpea (K25:C75), 100% kochia: 50% cowpea (K100:C50), 50% kochia: 100% cowpea (K50:C100), 100% kochia:100% cowpea (K100:C100), and 100% cowpea (C100). Dry forage yield, yield components, percentage of crude protein (CP), ash, acid detergent fiber (ADF), and dry matter digestibility (DMD) were measured in Kochia plants. Additionally, in cowpea, economic and biological yield, the number of pods per plant, and the 1000-grain weight were measured. To assess the profitability of intercropping, the land equivalent ratio (LER) was utilized.Results and DiscussionAccording to the obtained results, the planting pattern had a significant effect on the yield of kochia and cowpea, as well as the morphological characteristics of cowpea, including height, lateral branch, stem weight, and leaf weight. Additionally, the planting pattern had a significant effect on the quality parameters of forage, including the percentage of protein, ash, ADF, and DMD of Kochia. The highest yield was obtained for kochia (22,788 kg.ha-1) in the cropping pattern of K100:C100, and for cowpea (3590.3 kg.ha-1) in pure cowpea. The highest percentages of protein (19.90) and ash (14.83) were achieved in the additive intercropping pattern of K100:C100. It also achieved the highest and lowest percentage of DMD (41%) and, ADF (41.30%), respectively, in the pattern of K100:C50. The research results indicated that the highest LER (1.80) was achieved from the treatment of K50:C50.ConclusionThe yield and quality of forage in dry areas have significant importance, considering the prevailing climatic conditions. Therefore, intercropping is considered a practical solution to achieve the mentioned goals. or Despite the numerous benefits of intercropping, the selection of compatible forage and companion plants that are suitable for specific regional conditions, combined with the design of an appropriate cropping pattern, can greatly enhance the yield and efficiency of this cultivation system. According to the results, intercropping demonstrates higher forage quality compared to the sole crop of Kochia. High-quality forage has higher percentages of CP, ash, and DMD while having lower levels of ADF. Based on these findings, the additive patterns K100:C100 and K100:C50 are recommended. The research results indicate an increase in the quantitative and qualitative characteristics of both kochia and cowpea in intercropping. The LER in all replacement patterns was greater than one, indicating an increase in land efficiency compared to the sole crop. As a result, the natural potential of Kochia, a salt-tolerant plant, can be used as a suitable strategy for using saline soil and water resources and feeding livestock in the Zabol region.
Abstract
Background and aims
Intercropping of grain legumes and cereals in European agriculture can provide benefits, such as an increase in yields, yield stability and weed suppression. Interactions ...between crops in intercropping may depend on spatial heterogeneity in soil conditions, which are present on farmers’ fields. Understanding the effect of within-field variation in soil conditions on interspecific interactions might increase the benefits of intercropping by within-field adjustment of the agronomic management.
Methods
Crop performance and weed dry matter were assessed together with several soil properties in grids within three large field experiments at two sites (Germany and Sweden) and during two years. Each experiment was comprised of several strips sown either with the two sole crops oat (
Avena sativa
L.) and field pea (
Pisum sativum
L.) or an oat-pea intercrop.
Results
The response of crop performance to within-field variability in soil conditions was mostly species-specific. Yield stability of intercropping was consistently higher compared with pea, but not compared to oat. The highest land equivalent ratio was found for an additive intercropping design under a higher water availability. In this experiment, yield stability of both intercropped pea and oat were lower, which might be expected as a result of within-field variation in interspecific interactions. Intercropping reduced weed dry matter compared to pea, for which one experiment indicated an increase in weed dry matter with nutrient availability.
Conclusion
The experimental design and the developed statistical analysis can contribute to further research about spatial variations in interspecific interactions in intercropping, which will improve the understanding of plant-plant and plant-soil interactions.
•Agroforestry systems (AF) with narrow rows were compared with sole crops.•AF caused an overall decrease in yield and protein content of understory crops.•Yield and protein content of understory ...crops and PAR were highest in the center.•The AF systems may provide greater long-term economic benefits.
The objective of this study was to determine the effects of agroforestry systems with narrow rows on microclimate, crop quality, productivity, and revenue when compared with that in sole-cropping in drylands. Therefore, two-year field experiments were conducted to determine the characteristics of two types of agroforestry systems in drylands of Xinjiang including photosynthetically active radiation (PAR), air temperature, crop protein content, productivity, and revenue. The two systems included (1) a jujube tree (Zizyphus jujuba Mill.) + wheat (Triticum aestivum L.) intercropping (JWI) system and (2) a poplar tree (Populus L.) + alfalfa (Medicago sativa L.) silvopastoral (PAS) system located in southern and northern Xinjiang, respectively. Variables were measured in control sole-cropping plots and in the alleys of JWI and PAS system plots at different distances from the tree row. PAR and air temperature both decreased in plots of the JWI and PAS systems. The changes in microclimatic conditions and competition for resources in the JWI and PAS systems resulted in an overall decrease in wheat grain and alfalfa hay yield and decreases in the overall protein content of wheat grain and alfalfa. In JWI and PAS systems, the yield and protein content of understory crops, PAR, and air temperature were highest at the center line of the system alley and decreased with decreasing distances from the tree row. The PAS system was more productive than the JWI system based on the calculated land equivalent ratio (LER), because no significant decrease was observed in tree yield in the PAS system. Both the JWI and PAS systems resulted in an increase in the annual total crop revenue when compared with individual crop management, indicating that the JWI and PAS systems could provide greater long-term economic benefits. Therefore, the balance between yield, crop quality, and revenue have to be taken into account in the analysis of agroforestry systems.
PDF
