Intercropping pasture with grain crops provides a strategy for diversifying cropping systems and establishing a foundation for mixed crop-livestock farming systems.
Investigating the effects of strip ...design and nitrogen (N) application on interspecific interaction, crop yield, N use efficiency (NUE), and land equivalent ratio (LER) in dryland wheat/alfalfa intercropping.
We conducted a four-year field experiment, which tested three intercrops, namely, 2-row wheat with 1-row alfalfa (I21), 4-row wheat with 2-row alfalfa (I42), and 8-row wheat with 4-row alfalfa (I84), as well as sole wheat (SW) and alfalfa (SA). N rates of 150 (HN) and 75 kg ha−1 (LN) were applied for wheat.
Winter wheat exhibited earlier spring green-up than alfalfa and maintained dominance during co-growth. Over the four seasons, I21, I42, and I84 resulted in wheat yield (based on the wheat strip area) increases of 19.0%, 16.7%, and 24.0%, respectively, under HN, and 34.1%, 31.9%, and 43.4% under LN. Alfalfa growth was constrained during co-growth but recovered after the wheat harvest. Alfalfa in I42 and I84 maintained forage yield (based on the alfalfa strip area) as high as SA. Intercropping increased wheat NUE under both N conditions but did not significantly affect alfalfa NUE. I84 attained the highest LER of 1.01–1.14 and 1.11–1.25 under HN and LN respectively. Net revenue of I84 was lower than SA but three times higher than SW.
Wide-strip wheat/alfalfa intercrop with low-N showed the best performance, which is promising in diversifying farming system and improving agricultural sustainability.
•Wheat yield improvement was more significant under low nitrogen.•Intercropping increased both wheat ear density and 1000-grain weight.•Land equivalent ratio of wheat/alfalfa intercrop ranged in 0.79–1.31.•Wheat/alfalfa intercropping had higher yield and land advantage under low nitrogen.•Intercrop of 8-row wheat and 4-row alfalfa with low N was suggested for application.
•Increasing irrigation intervals resulted in higher soil temperatures.•Glycine betaine had an inhibitory effect against temperature stress.•Saffron + white bean intercrop reduced soil temperature ...compared to pure saffron.
The saffron dormancy period begins after drying above-ground parts, including actual and apparent phases. The differentiating reproductive organs during apparent dormancy need to be induced under optimal temperature conditions, while saffron farms are free of vegetation after the drying phase. Covering the soil surface during the summer season may be advantageous to counter such a major constraint. The current study was conducted at the experimental station of the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, from 2018-to 2019 and repeated from 2019-to 2020. A split-split plot arranged in a randomized complete block design with three replicates was used. Limited moisture of white bean (10 d irrigation as lower interval and 20 d irrigation as higher interval), glycine betaine foliar application (0 and 10 mM), and planting patterns (sole saffron, sole white bean, and saffron + white bean intercrop) were considered as the main plot, subplot, and sub-sub plot, respectively. Higher irrigation intervals resulted in increased soil temperatures, while glycine betaine had an inhibitory effect against heat stress. The Saffron flower number significantly improved after applying 10 mM glycine betaine. Furthermore, the maximum middle- (5–10 g) and large-sized (> 10 g) daughter corms and land equivalent ratio were recorded when 10 mM glycine betaine was applied in saffron + white bean intercrop. A similar response was also recorded in N and P concentration in the middle- and large-sized daughter corms. Considering the water restriction in arid and semi-arid areas, saffron-white bean intercropping, concurrent with 10 mM glycine betaine application, can play a pivotal role in regulating soil temperature and increasing land equivalent ratio.
Plant breeding for intercropping is lagging because most varieties currently available in the market are selected for sole cropping systems. The present study analyzed the response of durum wheat (12 ...varieties) and faba bean (3 varieties) in pure and mixed cropping. Field trials were conducted in 2019 and 2020. The performance of each variety in mixed and pure cropping was evaluated using both univariate and multivariate analyses of the grain yield and land equivalent ratio (LER). For durum wheat, grain protein content was also evaluated. Durum wheat varieties were characterized by good performance in both years, whereas faba bean varieties were more affected by the growing season, suggesting that much breeding effort is warranted to improve the latter as a pure and mixed crop. Moreover, the relative performance of all varieties was affected by their combination in mixed cropping, as evaluated based on the ratio (LERratio) between LER for wheat (LERw) and LER for faba bean (LERfb). To further evaluate the overall performance of wheat and faba bean in mixed cropping, total yield, LERtotal (LERw + LERfb), and ln(LERratio) were subjected to principal component and cluster analyses. The first principal component combined the total yield and LERtotal in a single index of the overall performance of each mixed crop combination. The second principal component, based on ln(LERratio), highlighted the relative performance of varieties in each mixed crop combination. The proposed multivariate approach can be applied in the breeding programs for intercropping to identify variety combinations based on crop performance and the relative importance of the proportion of cereal and legume grains in the total harvest.
Intercropping has great potential for alleviating arable land competition, improving land output and promoting sustainable agricultural development. However, the applicability of maize-soybean strip ...intercropping under drip fertigation in arid northwest China remains unclear, especially under various row configurations. A two-season (2022 and 2023) field experiment was performed in the Hexi Region of northwest China to investigate the responses of plant growth, yield performance, water-land productivity and economic profit of drip-fertigated maize-soybean strip intercropping systems to eight row configurations. The results showed that intercropping significantly reduced aboveground biomass accumulation of maize and soybean by 18.77% and 47.81% on average compared to monocropping, respectively. Intercropping significantly decreased the 100-grain weight, ear length and ear width of maize, and reduced the 100-grain weight and pod number of soybean, resulting in reduced grain yields of intercropped maize and soybean (by 13.08% and 48.73%, respectively), but two rows of maize alternating with four rows of soybean (M2S4), three rows of maize alternating with four rows of soybean (M3S4), four rows of maize in wide and narrow rows alternating with four rows of soybean (M4S4-MN), and four rows of maize in wide and narrow rows alternating with six rows of soybean (M4S6-MN) produced greater population grain yield compared to monocropping. Among all intercropping systems, the largest water-land productivity and economic profit occurred in M2S4 (1.61 in 2022 and 1.42 in 2023 for land equivalent ratio; 29.23 kg ha−1 mm−1 in 2022 and 28.22 kg ha−1 mm−1 in 2023 for water productivity; 23,965 CNY ha−1 in 2022 and 23,059 CNY ha−1 in 2023 for economic profit), followed by M4S4-MN (1.53 in 2022 and 1.36 in 2023 for land equivalent ratio; 27.11 kg ha−1 mm−1 in 2022 and 26.58 kg ha−1 mm−1 in 2023 for water productivity; 22,327 CNY ha−1 in 2022 and 22,224 CNY ha−1 in 2023 for economic profit). The M2S4 is thus the optimal row configuration for drip-fertigated maize-soybean strip intercropping systems in terms of grain yield, economic profit and land productivity, while the M4S4-MN is recommended by further considering the efficiency of mechanized sowing and harvesting.
•Intercropping reduced maize and soybean aboveground biomass compared to monocropping.•Intercropping decreased maize and soybean grain yields by 13.08% and 48.73%, respectively.•Water-land productivity and economic profit peaked in two maize rows alternating with four soybean rows.•M2S4 and M4S4-MN are suitable for drip-fertigated maize-soybean strip intercropping.
The relative intensity of facilitative effect among coexisting plant species is frequently affected by soil water and nutrient availability, such as nitrogen (N), phosphorus (P), potassium (K), and ...organic fertilizer. However, to date, the general pattern of nutrient gradient effects on plant–plant interactions remains inconsistent or even opposite in the intercropping systems. To address this issue, we performed a global meta-analysis and three experiments to investigate the production efficiency of intercropping along fertilizer input gradient (low vs. high) by assessing the land equivalent ratio (LER). Trial 1 included five P gradient in the maize–grass pea intercropping system. Trial 2 consisted of two N gradient in the maize–wheat, maize–soybean and wheat–soybean intercropping systems. Trial 3 contained two water and three P gradients in the same intercropping systems as Trial 1. The meta-analysis result indicated that the average LER for yield (LERY), biomass (LERB), N uptake (LERN), and P uptake (LERP) were 1.49, 1.25, 1.35, and 1.66, respectively. It implied that intercropping would save 49 %, 25 %, 35 % and 66 % lands to achieve the same yield, biomass, N and P uptake amount as monoculture, respectively. Also, high fertilizer inputs significantly decreased the relative productivity and nutrient uptake. Average effect sizes of high inputs on LERY, LERB, LERN, and LERP were up to − 0.0505 (−0.0550 to −0.0461), − 0.0267 (−0.0303 to −0.0230), − 0.0321 (−0.0395 to −0.0247) and − 0.0237 (−0.0370 to −0.0103), respectively. These negative values demonstrated that the LER markedly declined under the high-nutrient conditions. On the other hand, the results of Trial 1 confirmed that the LERY, LERB, LERN, and LERP tended to decrease significantly with increasing P addition. In Trial 2, the LERY of intercropping systems tended to significantly decrease with increasing N application. In Trial 3, the LERY, LERB, LERN, and LERP also displayed a descending trend with increasing P addition and soil water availability. Collectively, the three trials confirmed the reliability and universality of the meta-analysis conclusions. This study provided a broad support for the hypothesis of the nutrient-dependent relative benefits in intercropping systems.
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•Average land equivalent ratio was greater than 1 in meta-analysis database.•High nutrient input decreased the land equivalent ratio relative to low input.•Field and pot-culture trials confirmed the reliability of meta-analysis results.•Relative productivity benefits were species specific and context dependent.•Results confirmed the universality of stress gradient hypothesis in intercropping.
The three-dimensional nature of agrophotovoltaic systems (APV) accounts for the needs of photovoltaic power generation and agricultural production. The combination can solve conflicts among ...utilization of resources, ecological protection, and agricultural production to achieve low-carbon economic development. However, the economically respond (crop yield and quality) of different species under the decreased light available system is still unclear. To provide insights, we compared agrophotovoltaic and traditional ecosystems to explore the economic feasibility of planting Bupleurum chinense (B. chinense) and Medicago sativa (M. sativa) from the perspectives of light utilization, photosynthetic responses, and land use. The combined system improved the land equivalent ratio, net income and species quality of B. chinense and M. sativa. Both species showed high plasticity, and maintained growth and development by regulating their morphology and photosynthetic parameters. B. chinense in the APV increased its light use efficiency, photosynthetic rate, and root biomass by increasing its height, electron transfer flux, and up-regulating a photosystem I protein (PsaA). M. sativa in the APV allocated more energy to photochemical reactions to improve photosynthetic capacity. It captured and utilized the limited light by reducing leaf mass per unit area and dark respiration, increasing the chlorophyll content, and down-regulating a photosystem II protein (PsbD). Our results showed the importance of species selection based on morphological and photosynthetic responses and provide insights into the selection of appropriate species, efficient resource utilization, and sustainable economic development based on APV.
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•Bupleurum chinense and Medicago sativa maintained biomass accumulation and quality.•Bupleurum chinense increased photosynthesis by adjusting electron flux and PsaA.•Medicago sativa increased light capture area and protected photosystem II activity.•The agrophotovoltaic ecosystem increased the land use efficiency of both species.•Bupleurum chinense was more adaptable and improved economic benefits most.
Wheat-maize (W-M) double cropping is the dominant land use system in the North China Plain (NCP). This system has high grain output but suffers from high fertilizer input and nitrogen (N) surplus. ...Meanwhile, the market demands more protein and oil crops, such as soybean or peanut.
Here, we assess whether incorporation of legumes into W-M via intercropping with maize can contribute to lower annual N input while maintaining high annual outputs and diversifying products with high yield stability.
We compared yield, yield stability, and profitability of six rotation systems: W-M30 (at the maize inter-plant distance of 30 cm), the density-increased W-M20, wheat-soybean (W-S), wheat-peanut (W-P), and wheat with an intercrop of maize (at the inter-plant distance of 20 cm) and soybean (W-MS) or peanut (W-MP). Four annual N input levels were compared: N0 (no N input), N1 (reduced N input), N2 (target practice), and N3 (current high input).
Results over four years showed that replacing maize by maize/legume intercrops had a similar wheat yield as that of W-M while the N input was intermediate between W-M and W-legume rotations. Total actual/equivalent grain yields and gross margins of W-MS or W-MP were consistently intermediate between W-M and W-legume rotations. Intercropping enhanced the yield and temporal yield stability of maize per plant, with benefits for both yield stability of the intercropping system of maize season and the annual rotation system. Averaged over six rotation systems, increasing N supply increased the annual total actual/equivalent grain yield, gross margin and yield stability to a plateau starting at N1 or N2, without a further significant increase at N3. Specifically, the response of total equivalent yield or gross margin of each annual system to increasing N supply could be fitted by the linear-plateau model. Compared to the response curve of W-M, W-MS and W-S reached the plateau with a lower N input and higher yield and profit, while W-MP and W-P reached the plateau with lower N input but decreased the yield and profit. Compared to W-M with 240–360 kg N/ha/year, W-MS used 210–320 kg N/ha/year saving 11.1–12.5% fertilizer N, while maintaining or improving production by 9.1–13.0%, and improving profitability by 12.1–15.6% and temporal yield stability by 12.8–50.6%.
W-MS diversifies products with lower N input and higher outputs, profitability, and temporal yield stability than conventional W-M, thus is highly recommended towards productive and sustainable agriculture in the NCP.
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•The sustainability of wheat-maize (W-M) rotation is threatened by excessive fertilizer input and nitrogen (N) surplus.•Integration of legumes in W-M via intercropping was proposed to lower N input with high outputs and yield stability.•Yield, yield stability and profitability were compared among six rotations (with legumes and without) under four N levels.•W-M with soybean intercropping (W-MS) saved N input and had higher yield, profit and yield stability than W-M.•W-MS with moderate N application could replace conventional W-M in the North China Plain for its comprehensive performance.
•A menu of legume intercrop options for subsistence farmers in Nepal was tested.•Maize + cowpea, millet + soybean, wheat + pea, mustard + pea, and ginger + maize – soybean appeared to be ...productive.•Seasonal intercropping increased yield by 16–30% and potential income by 15–288%.•Ginger + maize – soybean was an innovative year-round option in the mid-hills.•Intercropping appeared to be a viable option to intensify terrace agriculture.
Low nitrogen inputs, low crop yield, and low land productivity are major challenges associated with cereal-based sole cropping systems in Nepal. Crop intensification and diversification by introducing legumes as intercrops could help alleviate these challenges. With the presence of diverse crops and cropping systems, particularly in hilly topographies, a range of intercrop options is required. We compared 10 intercrop combinations to native sole cropping systems in the mid-hills of Nepal for two cropping seasons (2015–2017) to identify the most productive and economic intercrop combinations for smallholder terrace agriculture. In the spring-summer season (i.e., mid-March to mid-July), cowpea (var. Makaibodi and Suryabodi) and bean were intercropped with maize in 1:1 rows, whereas soybean, blackgram, and horsegram were broadcast with millet (30:70 ratios) during the rainy-autumn season (i.e., mid-July to mid-November). Pea and lentil were used as pre-winter/winter intercrops (i.e., mid-November to mid-March) in mustard (30:70 ratios), while wheat was planted with pea. Ginger was planted with maize in 1:1 rows during the spring-summer season in which the maize rows were replaced by soybean and lentil during the rainy-autumn and pre-winter/winter season, respectively. Plots were analyzed for yields of individual crops as well as other agronomic indicators including land equivalent ratio (LER), total land output (TLO), harvest index (HI), and potential economic return.
Maize + cowpea var. Makaibodi appeared to be the most productive and economic intercrop combination for the spring-summer season (LER – 1.58 and TLO – 4.26 t ha−1, 21% higher than the maize sole crop with an increase in potential economic return by 67%) whereas millet + soybean appeared to be the best combination for the rainy-autumn season (LER – 1.40 and TLO – 2.21 t ha−1, 26% higher than the millet sole crop with a 288% increase in potential income). For the pre-winter/winter season, wheat + pea and mustard + pea combinations appeared to be productive (wheat + pea: LER – 1.31 and TLO – 2.90 t ha-1 i.e., 16% higher than sole wheat with a 54% increase in potential income; mustard + pea: LER – 1.36 and TLO – 2.14 t ha−1 i.e., 30% higher than sole mustard with a 15% increase in potential income). The year round intercrop system (i.e., ginger + maize-soybean) displayed a LER value of 2.45 with increased TLO (21.8 t ha−1 i.e., 2% higher compared to sole ginger) which increased potential economic return by 6%. We conclude that legume intercropping was a robust option across seasons and locations confirming that it could be a promising ecological practice for intensification of cereal-based sole cropping systems on smallholder terraces. Also, it is important to note that soybean and pea provided higher potential net income to farmers as sole crops compared to when they were grown with millet and wheat as intercrops, respectively. It is important that we promote these options to smallholder farmers and disseminate the advantages of legume integration on land productivity, soil fertility management, and income.
Soils provide key ecosystem services and are crucial to combat climate change. Agriculture provides important ecosystem services but also causes negative environmental effects depending on ...agricultural management. In this regard, crop diversification is a promising sustainable land management strategy to combat soil erosion and degradation, mitigate climate change and ensure food security. Here, we assess the combined short-term effects of crop diversification and no tillage on several key soil physico-chemical parameters related to soil functioning as well as on crop yields in a rainfed almond (Prunus dulcis Mill.) orchard under semiarid Mediterranean conditions. Almond trees were inter-cropped with Capparis spinosa L. (caper) or Thymus hyemalis Lange (winter thyme) and compared with the almond monocrop system. The experimental design consisted of three plots in a randomized-block design, with three replicates for each crop management treatment (almond monocrop, almond inter-cropped with caper, and almond inter-cropped with winter thyme). Along with crop yields, the combined effects of crop diversification and no tillage on a range of soil quality and health indicators including soil physical (bulk density, aggregate stability, water retention and availability) and chemical (total and particulate organic carbon and nitrogen, ammonium and nitrate content, available macro- and micro-nutrients) properties were monitored in the topsoil and subsoil (at 0–10 and 10–30 cm depth, respectively) one and three years from establishment.
from this study indicate that soil water retention capacity and water availability for plants were enhanced in both crop diversification systems after three years from their implementation at 0–30 cm depth. Likewise, improvements in particulate organic carbon and available N were observed in the subsoil of both crop diversifications. Crop diversification did not significantly affect the main crop yields, highlighting that crop diversification can be a promising sustainable management practice for improving soil health without compromising food security under semiarid Mediterranean conditions. Indeed, land equivalent ratios (LER) of almond trees inter-cropped with winter thyme were higher than those of their respective monocrop systems for two consecutive years, indicating that inter-cropping with aromatics can improve the productivity of rainfed woody monocrop systems under semiarid conditions. Our results emphasize the importance of selecting an appropriate secondary crop that ensures a permanent soil cover while contributes to enhance the agroecosystem productivity from the first year of establishment onwards to off-set plausible lower yields from the main crop. In this regard, preliminary assessments on soil condition and crop nutrient requirements are encouraged before designing and implementing a crop diversification in these low-input cropping systems.
Likewise, long-term studies are needed to provide evidence on the stability of the production of diversified crop management, particularly in these low-input cropping systems under harsh environmental conditions.
•Crop diversification impacts on land productivity and soil functioning were assessed.•Almond trees were inter-cropped with caper or thyme under semiarid conditions.•Inter-cropping enhanced soil structure and water and nutrient availability for plants.•Inter-cropping with aromatics improved land productivity of a rainfed almond orchard.•Soil and crop nutrient requirement assessments are encouraged before inter-cropping.
Protective roles of shade trees for climate-resilient cacao appear to depend on tree-site matching. Agroforestry practices involve a wide range of context-specific management options, which can be ...complex and pose challenges due to tradeoffs.
To assess the benefits and drawbacks, across a range of contexts, of various cacao-based land use systems on multifunctionality and economic performance.
We used the process-based Water, Nutrient and Light Capture in agroforestry systems (WaNuLCAS) model to assess the performance of five cacao-based land use systems (cacao monoculture, cacao + annual crops, cacao + fruit tree, cacao + fast-growing tree, and cacao + slow-growing tree), in three climate regimes (tropical rainforest, monsoon, and savannah), two soil textures, and two sources of data for cacao root length density (W Africa and Indonesia, respectively). Several metrics quantified the performance of each land use system, including the Land Equivalent Ratio for production (LERP),multifunctionality (LERM), Net Present Value (NPV), Return to Labour (RtL), and Benefit-Cost Ratio (BCR).
Simulated cacao production per tree, positively or negatively influenced by intercrops, responded to the number of days cacao grew under water-limited conditions. High cacao root density supported higher LERP values (an average of 1.15 versus 0.95 in other cases). In the savanna, the LERP difference between cacao with high root density and those with low root density became 0.27. Among agroforestry systems, cacao + annual crops had the highest LERP of 1.13, followed by cacao + slow-growing trees (1.09), while the lowest outcome (0.98) was for cacao + fruit trees. These values were higher in rainforest climates, and lowest for savanna. Soil texture had no effect on the average LERP across other main factors. Tree-based agroforestry had a higher time-averaged carbon stock than monocultures or systems with annual crops. However, their effects on other environmental performance aspects, averaged over a 20-year life cycle, were modest, and variation in LERM was small. Economic performance indicators diverged, with the highest NPV were for cacao + annual crops or cacao + fruit trees, the highest BCR was for cacao + fruit trees, and the highest RtL was for cacao + fruit trees followed by cacao + slow-growing trees.
Our study highlights that the potential benefits of cacao-based agroforestry practices depend on strong root development by the cacao trees. In selecting for high yields in monocultures, the benefits of intercropping may be forfeited, especially in drier climates with the lower values for root length density measured in W Africa.
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•Cacao can have annual food crops, fruit trees, slow- or fast-growing timber trees as companion plants.•Cacao agroforestry options depend on rainfall, soils and cacao root development.•A calibrated WaNuLCAS model estimated multifunctionality and economic performance.•Integrating cacao with fruit trees achieves best economic performances.•Selection for high-yielding cacao with low belowground C investment, forfeits intercropping options.
