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Maize/peanut intercropping may improve soil health through reducing nitrogen (N) fertilization. However, the effects of maize/peanut intercropping combined with reduced N fertilization on the soil fungal community structure have not been well reported. Using a long-term localized micro-zone experiment, we investigated the combined effects of intercropping and N fertilizer application on soil fungal community diversity and composition. Three cropping patterns (maize/peanut intercropping, maize monoculture, and peanut monoculture) and three N application levels (0 kg·hm−2, 150 kg·hm−2, and 300 kg·hm−2) were assessed. The results showed that the total numbers of fungal species and unique species (operational taxonomic units, OTUs) in both maize and peanut soils tended to first increase and then decrease with increasing N application. Compared with monoculture, the numbers of total OTUs and unique OTUs in intercropped maize soil decreased by 4.14% and 12.79%, respectively, but the total numbers of OTUs and unique OTUs in peanut soil increased by 1.08% and 3.78%, respectively. With increasing N application, the soil fungal Ace and Chao indices of maize soil first increased and then decreased, while the fungal Shannon, Ace, and Chao indices of peanut soil decreased. Compared with the monoculture system, intercropping significantly reduced the maize soil fungal Ace and Chao indices but increased the peanut soil fungal Shannon, Ace, and Chao indices. Nitrogen application and intercropping significantly altered the fungal community structure of maize soil, while N application had no significant effect on the fungal community structure of peanut soil, though intercropping significantly changed the fungal community structure of peanut soil. At the phylum level, Ascomycota, Basidiomycota, Mortierellomycota, unclassified_k_Fungi, and Chytridiomycota were the dominant taxa. Redundancy analysis (RDA) showed that soil nitrate (NO3−) content was the main environmental factor shaping the soil fungal community. In conclusion, excessive N fertilization (300 kg·hm−2) can reduce soil fungal community diversity; maize/peanut intercropping reversed the negative effect of N application on fungal community of peanut soil, but not that of maize soil. Soil NO3− content is the primary environmental driver of soil fungal communities. [ABSTRACT FROM AUTHOR]

Maize/peanut intercropping is practiced widely to increase land productivity and considered a sustainable way for using and saving resources through peanut's complementary N source via biological N2 fixation. Our study aims to understand how maize/peanut intercropping affects the nodulation of peanuts under water-limiting conditions and different nitrogen inputs. A two-year micro-plot experiment in 2015–2016 and a two-year field experiment in 2017–2018 were conducted to quantify nodulation in maize/peanut intercropping and sole peanut cropping under four N fertilization rates (N-free, low, medium, and high N) in rain-fed water-limited conditions. In the micro-plot experiment, intercropped peanuts increased nodule biomass compared to sole peanuts. The nodule number of intercropped peanuts was 51.6% (p = 0.001) higher than that of sole cropped peanuts, while nodule weights did not differ at high N fertilization rates and were lower in the no-N fertilization control. However, the results were different in the field experiment. Both the nodule number and single weight of the sole cropped peanut were 48.7% (p = 0.020) and 58.9% (p = 0.014) higher than that of the intercropped peanut. The ratio of the nodule weight to aboveground dry matter at the beginning peg in the dry year of 2017 was lower in intercropping than sole cropping, especially at low N fertilization rates. The potential increase in nodulation found in a well-controlled micro-plot environment might be limited by strong water and light competitions in field conditions. The results could contribute to the understanding of interspecific interactions in cereal/legume intercropping. [ABSTRACT FROM AUTHOR]

Highly diverse exoenzymes mediate the energy flow from substrates to the multitrophic microbiota within the soil decomposer micro‐food web. Here, we used a "soil enzyme profile analysis" approach to establish a series of enzyme profile indices; those indices were hypothesized to reflect micro‐food web features. We systematically evaluated the shifts in enzyme profile indices in relation to the micro‐food web features in the restoration of an abandoned cropland to a natural area. We found that enzymatic C:N stoichiometry and decomposability index were significantly associated with substrate availability. Furthermore, the higher Shannon diversity index in the exoenzyme profile, especially for the C‐degrading hydrolase, corresponded to a greater microbiota community diversity. The increased complexity and stability of the exoenzyme network reflected similar changes with the micro‐food web networks. In addition, the gross activity of the enzyme profile as a parameter for soil multifunctionality, effectively predicted the substrate content, microbiota community size, diversity, and network complexity. Ultimately, the proposed enzymic channel index was closely associated with the traditional decomposition channel indices derived from microorganisms and nematodes. Our results showed that soil enzyme profile analysis reflected very well the decomposer food web features. Our study has important implications for projecting future climate change or anthropogenic disturbance impacts on soil decomposer micro‐food web features by using soil enzyme profile analysis. Highlights: Soil enzyme profile analysis for indicating decomposer micro‐food web features was first proposed.Diversity indication utilities for contrasting enzyme profiles were different.Protozoa channel index and enzymatic channel index were proposed. [ABSTRACT FROM AUTHOR]

Polycaprolactone (PCL) is one of the promising linear aliphatic polyesters which can be used as mulching film. Although it has suitable glass transition temperature and good biodegradability, further practical applications are restricted by the limited temperature-increasing and moisturizing properties. The rational design of the PCL structure is a good strategy to enhance the related properties. In this study, thermally-induced phase separation (TIPS) was introduced to fabricate a PCL nanoporous thin film. The introduction of a nanoporous structure on the PCL surface (np-PCL) exhibited enhanced temperature-increasing and moisturizing properties when used as mulch film. In detail, the average soil temperature of np-PCL was increased to 17.81 °C, when compared with common PCL of 17.42 °C and PBAT of 17.50 °C, and approaches to PE of 18.02 °C. In terms of water vapor transmission rate, the value for np-PCL is 637 gm−2day−1, which was much less than the common PCL of 786 and PBAT of 890 gm−2day−1. As a result, the weed biomass under the np-PCL was suppressed to be 0.35 kg m−2, almost half of the common PCL and PBAT. In addition, the np-PCL shows good thermal stability with an onset decomposition temperature of 295 °C. The degradation mechanism and rate of the np-PCL in different pH environments were also studied to explore the influence of nanoporous structure. This work highlights the importance of the nanoporous structure in PCL to enhance the temperature-increasing and moisturizing properties of PCL-based biodegradable mulching film. [ABSTRACT FROM AUTHOR]

Returning corn stalks to the field is an important and widely used soil management practice which is conducive to the sustainable development of agriculture. In this study, the effects of corn stalks and urea on N2O production in corn field soil were investigated through a 21-day incubation experiment. This study showed that increasing amounts of urea added to soil with a history of corn cultivation leads to increasing overall N2O emissions, by increasing both the intensity and the duration of emissions. Although N2O production was affected primarily by urea-derived NH4+-N and NO3−-N, its main source was native soil nitrogen, which accounted for 78.5 to 94.5% of N2O. Returning corn stalk residue to the field reduced the production of N2O, and the more urea was applied, the stronger the effect of corn residue on reducing N2O emissions. Combining the application of corn stalks and urea could reduce the concentration of NH4+-N and NO3−-N derived from urea, and then reduce the substrate required for N2O production in nitrification and denitrification processes. In addition, the combined application of corn stalks and urea could effectively inhibit the abundance of key N2O-producing genes AOA amoA, nirS and nirK. [ABSTRACT FROM AUTHOR]

• Maize had greater leaf growth rate and longevity in maize/peanut intercropping. • Maize allocated greater dry matter into ear in maize/peanut intercropping. • Responses of growth to plant density for intercropped and sole maize were different. • Increasing maize plant density enhanced yield advantage in maize/peanut intercropping. Maize (Zea mays L.)/peanut (Arachishypogaea L.) intercropping has been widely practiced in semi-arid regions to reduce wind erosion and improve resource (e.g. water and light) use efficiencies. Knowledge on optimal maize plant density is lacking from perspective of dry matter accumulation among organs in this intercropping system. We quantified the effect of maize plant density on relative yield total (RYT), maize and peanut yields, and maize dry matter of organs (ears, leaves, and stems) in maize/peanut intercropping. Field experiments were conducted in a semi-arid area of China in 2015 and 2016. Three maize plant densities (6, 9 and 12 plants m−2) were tested in maize/peanut intercropping (per unit growing area designed for maize) and sole systems, whereas the plant density of intercropped peanut and sole peanut was fixed as 24 plants m-2. The beta and logistic growth functions were used to quantitatively characterize the dynamics of dry matter allocation among organs in maize. Increasing maize plant density significantly increased maize yield gain, but not increased peanut yield loss, in maize/peanut intercropping. The greatest yield advantage (RYTs of 1.21 in 2015 and 1.13 in 2016) occured in maize/peanut intercropping with maize planted at 9 plants m−2. Increasing plant density increased leaf growth rate, but reduced leaf longevity and dry matter allocation to ears for maize grown in both intercropping and sole systems. But, greater increases in leaf growth rate and leaf longevity for intercropped maize compared with sole maize resulted in a greater increase in dry matter accumulation for maize grown at 9 and 12 plants m−2. Greater increases in ear dry matter accumulation and yield were found for maize grown at 9 plants m−2 due to greater dry matter allocation to ears. We conclude that the different responses to plant density of the source capacity (leaves) and sink strength (ears) for maize in intercropping and sole systems could help optimize maize plant density (9 plants m-2) for greater maize yield gain and yield advantage in maize/peanut intercropping. [ABSTRACT FROM AUTHOR]

The use of biodegradable plastic film mulching as a replacement for polyethylene plastic film has gained recognition due to its reduced environmental pollution. However, its impact on soil environment is not yet fully understood. Here, we compared the effects of different plastic film mulching on the accumulation of microbial necromass carbon (C) and its contribution to soil total C in 2020 and 2021. Results showed that biodegradable plastic film mulching decreased the accumulation of fungal necromass C compared to no plastic film mulching and polyethylene film mulching. However, the bacterial necromass C and soil total C were not affected by the plastic film mulching. Biodegradable plastic film mulching decreased the soil dissolved organic carbon content after maize harvest. Random forest models suggested that soil dissolved organic C, soil pH and the ratio of soil dissolved organic C to microbial biomass C were important factors in regulating the accumulation of fungal necromass C. The abundance of the fungal genus Mortierella was also found to have a significant positive contribution to the accumulation of fungal necromass C. These findings suggest that biodegradable plastic film mulching may decrease the accumulation of fungal necromass C by changing substrate availability, soil pH, and fungal community composition, with potential implications for soil C storage. [Display omitted] • Biodegradable plastic film (PBAT) mulching decreased the fungal necromass carbon (C) in soil. • Soil dissolved organic C was the main factor the affect the accumulation of fungal necromass C. • Shift of the soil fungal composition have an effect on the accumulation of fungal necromass C. • Promoting of PBAT on a large scale may reduce soil C sequestration by decreasing fungal necromass C. [ABSTRACT FROM AUTHOR]

Highlights • Film cover during autumn and winter reduces evaporation and saves water. • Autumn and winter film cover increases yield and water use efficiency. • Increased soil water content promotes establishment and kernel filling. • Increased soil temperature due to film cover accelerates early growth. • Film cover increases yield stability and mitigates drought risks. Abstract Plastic film mulch increases crop yields in rain-fed agriculture in cool semi-arid climates by warming the soil and reducing evaporative water losses. The semi-arid Khorchin area in Northeast China is an important production area for rain-fed maize. Drought stress occurs frequently, even if plastic film mulch is applied at sowing. We hypothesized that the yield and water capture of maize could be increased by reducing evaporative loss of water by use of plastic film cover during the autumn and winter preceding sowing. In this study, we compared maize growth, water uptake and yield in three film cover treatments: (1) film cover from the autumn before maize sowing until maize harvest (autumn mulching: AM), (2) film cover from maize sowing till harvest (conventional practice) (spring mulching: SM), (3) no film cover (no mulch: NM). Field experiments were conducted in Fuxin city, Khorchin region, Liaoning province, China in 2013/2014 and 2014/2015. Autumn mulching increased grain yield on average by 18% when compared to spring mulching and by 36% when compared to no mulching. The 1000-kernel weight in AM was 7% higher than in SM, and 12% higher than in NM. Soil water content in the root zone before sowing was 35 mm greater in AM than in SM and NM. Water uptake during the growing season was 34 mm greater in AM than in SM and NM. Water use efficiency for grain yield (yield per unit water uptake) in AM was on average 2.5% higher than in conventional mulching (SM) and 27% higher than in NM. Autumn mulching advanced development, with an advance of 5 days in tasseling time as compared to SM and 10 days when compared to NM. These results show that film cover during the fallow period before maize sowing can increase crop yield and water use efficiency, and reduce climate risks in rain-fed agriculture under semi-arid conditions. [ABSTRACT FROM AUTHOR]

Agroforestry systems, which combine annual crops with trees, are used widely in semi-arid regions to reduce wind erosion and improve resource (e.g. water) use efficiency. Limited knowledge is available on optimizing such systems by the choice of crop species with specific physiological traits (i.e. C3 vs C4, N-fixing vs non-N-fixing). In this study we quantified the light interception and utilization efficiency of trees and crops in agroforestry systems comprising apricot trees and a C3 species (sweet potato), a C4 species (millet) or an N-fixing legume species (peanut), and used measurements in the sole stands as a reference. A significant delay in leaf growth was found in millet. Maximum LAI of millet was 17% higher in agroforestry then expected from sole crop LAI, taking into account the relative density of 2/3, while a 25% decrease in maximum LAI compared to expected was observed in peanut and sweet potato. The total light interception in agroforestry was 54% higher than in sole tree stands and 23% higher than in sole crops. The millet intercepted more light and produced more biomass in agroforestry than peanut and sweet potato. The LUE values of the crops in the mixed systems were higher than those of the sole crops, as was the photosynthetic efficiency of individual leaves, especially in plants in the border rows of the crop strips. High light capture in agroforestry made a greater contribution to productivity of understory crops than the increases in light use efficiency. We conclude that agroforestry systems with apricot trees and annual crops, especially millet, can improve light utilization in semi-arid climates and contribute to regional sustainability and adaptation to climate change. [ABSTRACT FROM AUTHOR]

Sustainable increases in food production in semi-arid regions require efficient use of land and water resources. Agroforestry is the practice of combining tree and crop cultivation on a land parcel and may increase both land productivity and water use efficiency. We conducted two years of field experiments in the semi-arid Khorchin region in Liaoning, China, to determine to which extent land and water use efficiencies were affected by mixing apricot ( Prunus armeniaca ) trees with annual crops: peanut ( Arachis hypogaea ), millet ( Pennisetum italica ) or sweet potato ( Ipomoea batatas ). Apricot yields were not significantly affected in the agroforestry, compared to the sole stand, but yields of the annual crops were lower when grown under trees than as sole crops, with relative crop yields of 0.46 for millet and 0.35 for both peanut and sweet potato in the agroforestry. Crop rows near tree rows had lower yields than crop rows further away from trees. Land equivalent ratios (LER) were 1.34, 1.44 and 1.33 in mixed systems with peanut, millet and sweet potato, respectively. Mixing crops and trees did not increase water extraction from the top 100 (2012) or 200 cm (2013) soil profile comparing to sole tree. Thus, with increased crop output and similar apricot yield, the water use efficiency was improved in the mixed system. Water use efficiency of the mixed system was characterized with the water equivalent ratio (WER). This index, analogous to LER, expresses the relative yield total per unit of water in the mixed system compared to the sole crops. WERs were 1.39, 1.51, and 1.34 in agroforestry systems with peanut, millet and sweet potato, respectively. We conclude that apricot-based agroforestry improves the productivity and water use efficiency of rain-fed agriculture in this semi-arid area, especially when a drought adapted crop such as millet is used. [ABSTRACT FROM AUTHOR]

The main objective of this study was to investigate the effects of combining subsoil and incorporation of corn stover on soil profile, soil physicochemical properties, and corn yield. A five-year field trial was conducted that consisted of two treatments arranged in a completely random design and replicated three times. Two soil management operations were tested: subsoil + corn stover incorporation (plow construction [PC] treatment) and conventional rotary tillage (control check [CK] treatment). Compared with rotary tillage, it was found that combining subsoil and corn stover incorporation significantly affected corn grain yield in all seasons. Further, combining subsoil and corn stover incorporation significantly increased the thickness of the plow layer, quantity of plow layer soil, thickness of the plow pan and soil bulk density, as well as soil organic matter, available nitrogen, available phosphorus, and available potassium. Evidence indicates that reconstructing the soil plow layer through combination of subsoil and corn stover incorporation improved soil structure, nutrient content, and corn yield. It is of interest that farmers are now applying subsoil and returning crop straw instead of solely relying on rotary tillage. [ABSTRACT FROM PUBLISHER]

Model simulated crop growth and productivity has been a widely accepted and powerful tool for assessing agricultural production in response to weather, soil, water and nutrients management. A water-driven AquaCrop model recommended by FAO can evaluate the various crops growing across climate, soil, water deficit and irrigation management conditions apart from surface soil mulching process. In this study, AquaCrop model for simulating maize (Zea mays L.) canopy growth, soil water utilization and grain yield formation of mulching maize with plastic film was developed in the northwest semi-arid region of Liaoning province, China (121.70°E, 42.11°N). Based upon invariance of growing degree days (GDD) principle, we modified mean daily air temperature calculation method of AquaCrop model for maize with plastic film mulch according to compensatory effect of cumulative soil temperature to cumulative air temperature, and calibrated this developed model using measured experimental data of growing days, water consumption and grain yield in 2011; the two-year experimental data from 2012 and 2013 were used to validate the developed model for simulating canopy cover (CC), soil water content (SWC); three-year filed experimental data from 2011 to 2013 were used to validate the developed the model for grain yield and water use efficiency under maize rainfed conditions. The modified calculation of air temperature showed that, depending on the linear regression relationship between mean daily air temperature and soil temperature (at 5cm depth) under plastic film mulching and non-mulching (R2>0.8), the raised soil temperature in the mulched maize field was remarkable before tasseling stage. The compensatory coefficient (Cmaize) of mulching plastic film maize and air increment of cumulative soil temperature to cumulative air temperature can be generated continuously by transparent algorithms, which Cmaize was 1.356 from sowing to emergence, 0.635 from emergence to tasseling stage, and 0 after flowing. Furthermore, mean daily air temperature with the addition of air increment formed a new file (*.tmp) and input to AquaCrop's climate module which can modify by function could be applied to mulching plastic film maize growing. Model coefficient of efficiency (CE), coefficient of determination (R2), the relative root mean square error (RRMSE), prediction error (Pe) and coefficient of residual mass (CRM) were used to test the model performance. The developed AquaCrop model was calibrated for simulating maize growing days, water consumption and grain yield for mulched and no-mulched maize with the prediction error statistics -4%0.88, 0.090.87. Upon validation, the Pe in simulation of water consumption and grain yield under mulched and no-mulched maize was among ±6%. In addition, R2, RRMSE, CE of grain and water use efficiency during 2011 to 2013 were 0.96 and 0.93, 0.042 and 0.06, 0.91 and 0.89, respectively. The developed AquaCrop model predicted maize grain yield with higher accuracy and performed better yield than water use efficiency for mulching plastic film maize, which indicated this improved model were better mechanism and application for simulated maize mulching. The present research implicated that the developed AquaCrop model can be applied to the same to semi-arid region and simulated maize potential, or prescribing yield in response to water and temperature limiting factors under climate change. [ABSTRACT FROM AUTHOR]

Plough layer construction is regarded as one of important methods for solving rainfed farmland problems. In order to explore the effect of plough layer construction on crop yield and water use efficiency (WUE) of spring maize, four tillage methods, including up loose and down compaction plough layer (ULDC, CK), all loose plough layer (AL), furrow loose and ridge compaction plough layer (FLRC) and all compaction plough layer (AC), were carried out in a long-term experimental station of Fuxin. The result showed that the yield of spring maize was significantly influenced by different plough layer constructions. For the years of 2011 and 2012, the maize yield under FLRC was the highest, followed by those under AL and CK; the yield under AC was the lowest. The average maize yield of the two years under FLRC was 16.39% higher than that under CK, and the yield under AL was 5.30% higher than that under CK, which were contributed by the increase in hundred kernel weight; the yield under AC was 5.73% lower than that under CK. The above-ground biomass (AGB) of maize and the harvest index were also examined. The result showed a significant impact of different plough layer constructions on AGB and harvest index of the maize. The FLRC treatment in 2011 was significant different from the others (P<0.05), while the difference between the treatments of AL and CK was not significant (P>0.05). The yield under FLRC was 7.18%, 7.19% and 12.87% higher than those under AL, CK and AC, respectively. The yield under FLRC in 2011 was generally consistent with that in 2012, without significant difference (P>0.05). The harvest indices for the four treatments ranged from 0.38 to 0.44. The findings also showed that soil moisture contents under of FLRC and AL were higher than those under AC and CK. The soil water storage (0-100 cm) under the four treatments (FLRC, AL, CK and AC) were 247.36, 248.97, 242.84 and 239.48 mm, respectively, indicating that FLRC and AL could efficiently loose soil, increase water penetration and soil water storage, and improve soil moisture contents significantly. For both normal year (2011) and wet year (2012), the soil under FLRC could utilize precipitation of growing season effectively, and promote precipitation use efficiency of maize. An 11.95% increase of rainfall use efficiency was observed under FLRC than that under CK in 2011; FLRC and AL showed the increases of 21.23% and 12.43% of rainfall use efficiency comparing to CK in 2012, respectively. WUE of the crops differed in different years and plough layer constructions. In 2011, a 15.68% increase in WUE was observed under FLRC comparing to that under CK, the similar trend was also appeared in 2012, a 23.13% increase for CK in WUE. Averaging the result of two year, an 18.43% increase in WUE was observed comparing to that of CK. Consequently, furrow loose and ridge compaction plough layer was an efficient construction for improving production and WUE of cropland in semi-arid zone of northeastern China. [ABSTRACT FROM AUTHOR]

• The average land equivalent ratio (LER) of maize/peanut intercropping was 1.31. • The high relative yield of maize contributed most to the high LER. • Maize/peanut intercropping attained on average a "win-no win" yield advantage. • PLER maize was increased when maize was sown earlier than peanut. • N input increased PLER maize and decreased PLER peanut while LER was not affected. Intercropping cereals and legumes can increase agricultural productivity and reduce inputs of nitrogen fertilizer but there is a need for further literature synthesis on the size of intercropping advantages and the factors affecting these advantages. Here we present a global meta-analysis of 36 studies, 66 experiments and 260 treatments addressing the land productivity of maize (Zea mays L.) and peanut (Arachis hypogaea L.) intercropping. Data were extracted from the literature and analyzed with mixed effects models to assess the land equivalent ratio (LER) and the factors affecting LER. The worldwide average LER of maize/peanut intercropping was 1.31 ± 0.03. The LER did not vary with continent, intercrop planting pattern and temporal niche differentiation, but sowing maize earlier than peanut (relative sowing time: RSTm<0) increased the partial LER of maize without significantly decreasing the partial LER of peanut. Increased N rate increased the partial LER of maize and decreased the partial LER of peanut but did not affect the total LER. This meta-analysis shows that maize/peanut intercropping is more land use efficient than the sole crops, it attains on average a "win-no win" yield advantage and mainly due to the maize. [ABSTRACT FROM AUTHOR]

• Crop yield respond positively to border rows proportion (BRP) for dominant maize but natively for understory peanut. • Kernel number of maize and pod number of peanut were the main yield components that responded to BRP. • Relative crop yields responded strongly to variation in BRP resulting from strip width of 1 to 4 m in maize/peanut intercropping. Strip intercropping enables increases in yields and ecological services in agriculture. Crop yields of species grown in strip intercropping are often related to the yield responses (increases or decreases) in the outer rows of the strips: the border rows. This suggests that the yield response can be modulated by changing the proportion of border rows in the field. Here we studied the relationship between component species yields and proportion of border rows in strip intercrops of maize (Zea mays L.) and peanut (Arachis hypogaea Linn.). We tested four different intercrops with equal proportions of maize and peanut but a different number of rows per strip: M2P2 (2 rows maize intercropped with 2 rows peanut), M4P4, M6P6, M8P8, and sole maize (SM) and sole peanut (SP). The border-row proportions were 1, 0.5, 0.33 and 0.25 for the intercropping M2P2 to M8P8, respectively, and 0 for the pure stands. Yield responded positively to the proportion of border rows for maize, but negatively for peanut, confirming the dominance of maize in this system. Kernel number per ear of maize and pod number per plant of peanut were the main yield components that responded to the border-row proportion. Across three years, relative maize yield (yield in intercropping divided by yield in monoculture), varied from 0.76 in M2P2 to 0.56 in M8P8, while relative peanut yield varied from 0.19 in M2P2 to 0.39 in M8P8. Relative yield total was not significantly different from one in any of the mixtures. Yield of intercropped maize in border rows was 48% higher than in inner rows and the sole crop, in part due to a significantly higher kernel number per ear (13%). Yield of intercropped peanut in border rows was on average 29% lower than in inner rows and 48% lower than in sole peanut. Yield responses in border rows were independent from the border-row proportion. The results show that relative crop yields responded strongly to variation in border-row proportion resulting from variation in strip width from 1 to 4 m. Strip width thus provides a mechanism to control the strength of interspecific plant interactions and relative yields in strip intercropping. [ABSTRACT FROM AUTHOR]