Peanut Intercropping Research Articles

Soil chemical characteristics and yield of red rice under aerobic irrigation system as affected by intercropping with peanut and application of organic wastes on permanent raised-beds

Intercropping with peanuts was reported to increase yield of cereal crops. The objective of this study was to examine the effect of peanut-intercropping and organic waste application on some soil chemical characteristics and red-rice yield under aerobic irrigation systems. The experiment was conducted from May to August 2020 in West Lombok (Indonesia), under Split Plot design, testing two factors, namely intercropping (T1=monocropped rice; T2=rice+peanut intercropping) in the main plots, and organic waste application (L0=without organic waste, L1=application of rice husk, L2=rice husk ash, L3=rice husk ash and cattle manure) in the subplots. Results showed that intercropping did not affect soil chemical properties but it significantly increased number of panicles and filled-grains, 100 grain weight, and grain yield of red rice per clump (31.27 g/clump under monocrop and 41.50 g/clump under intercropping with peanut). In contrast, organic waste application significantly influenced soil chemical characteristics and red-rice yield (the highest yield of 43.52 g/clump under L3). The significant interaction between factors on 100 grain weight indicated that the highest weight (2.89 g) was on intercropped red-rice under L3 treatment and the lowest one (2.18 g) was on monocropped red-rice under L2 treatment.

Canopy heterogeneity with border-row proportion affects light interception and use efficiency in maize/peanut strip intercropping

• Different border-row proportions (BRP) in maize/peanut intercropping were compared to mono crops. • Increasing BRP increased light interception (LI) of maize in the intercropping but not for light use efficiency (LUE). • Increasing BRP decreased LI but increased LUE of peanut in the intercropping. • LUE of both crops increased with leaf area index and decreased with light intensity. Intercropping usually plants two or more crop species, often with different canopy architectures by row configuration, creates spatial niche differentiation, changes light distribution and affects radiation utilization and yield. In this study, we investigated how row configuration (e.g. the proportion of border rows) affected light interception (LI) and light use efficiency (LUE) in maize ( Zea mays L.)/ peanut ( Arachis hypogaea Linn.) strip intercropping. Field experiments were carried out for two years in 2015 and 2016. Four intercropping treatments were set as M2P2 (two rows maize and two rows peanut), M4P4, M6P6 and M8P8, with border-row proportion (BRP) of 1, 0.5, 0.33 and 0.25 under an equal land use proportion (0.5 for each crop). Two monocultures, sole maize and sole peanut (with BRP of 0), were set as controls. The LI was estimated by a light interception model developed for strip intercropping. Both light capture and light use efficiency of intercropped crops were significantly affected by strip width. The LI of intercropped high-stalk maize was 23.4 % higher while LI of shaded peanut was 32.2 % lower than the control. The LI of intercropped maize increased with the increasing of BRP. The LI of peanut decreased with BRP but did not show significant difference in low BRP treatment (i.e. in M6P6 and M8P8). The LUE differed within treatments in dry 2015 but not in wet 2016. In dry 2015, LUE of intercropped maize on average 13.6 % lower than the sole crop (2.05 g MJ −1 ), while LUE of intercropped peanut especially in M2P2 was 23.9 % higher than the sole crop (0.73 g MJ −1 ). The LUE varied daily and was significantly correlated with leaf area index and incident radiation intensity in both intercropping and the sole crops. Both LI and LUE responded to BRP and the responses differed between intercropped crops. The result could be used as a basis for explaining the mechanism of strip intercropping on light utilization, optimizing row configuration of intercropping design and improving light use algorithm of crop simulation model.

Maize/peanut intercropping increases land productivity: A meta-analysis

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.

Comparison of Soil Biological Properties and Bacterial Diversity in Sugarcane, Soybean, Mung Bean and Peanut Intercropping Systems

Sugarcane intercropping with soybean [Glycine max (Linn.) Merr.], mung bean [Vigna radiata (Linn.) Wilczek] and peanut (Arachis hypogaea Linn.) as well as a sugarcane monoculture were conducted to study the impacts of intercropping on soil biological characteristics and bacterial diversity. The results showed that soil cultivable microorganisms, the activities of soil enzymes and microbial biomass carbon, nitrogen, and phosphorus were all significantly improved by intercropping with soybean and mung bean. Additionally, soil bacterial diversity and richness in sugarcane fields were also significantly enhanced by intercropping with soybean and mung bean. In addition, soil bacterial community structures in sugarcane fields can be altered by intercropping with different legumes. Proteobacteria, a high-nutrient-tolerant bacterial assemblage, became the dominant bacteria in the sugarcane-soybean and sugarcane-mung bean intercropped soils. Twenty four, 28, 26 and 27 dominant soil bacterial genera were found after the sugarcane-soybean, sugarcane-mung bean, sugarcane-peanut and sugarcane monoculture treatments, respectively. Sugarcane-mung bean intercropping being the most promising system for regaining and improving soil fertility and soil heath and facilitate agriculture intensification of sugarcane.

Seedling defoliation of cereal crops increases peanut growth and yield in an intercropping system

Intercropping cereals and legumes is practiced widely in the world for improving yields and economic benefits. Shorter legume crops in intercropping are shaded by taller cereals, substantially reducing legume growth and yield. Reducing shade in intercropping by shortening the plant height of cereals by seedling defoliation has been proposed as a practical approach to increase crop yields and land productivity. A two-year field experiment was conducted to investigate the effect of defoliation of cereal crops at seedling stage on the growth and yield of peanut (Arachis hypogaea L.) intercropped with corn (Zea mays L.) or millet (Setaria italica L.). In comparison with non-defoliation controls, defoliation reduced final plant height by 29 cm on average for corn and 18 cm for millet. Photosynthetically active radiation on peanut in intercropping systems with corn or millet intercropping was respectively 27.0% and 22.8% higher than those in controls, significantly improving the light environment of intercropped peanut. Net photosynthetic rates of peanut were on average 25.5% higher in corn and peanut intercropping and 19.6% higher in millet and peanut intercropping than those in non-defoliation controls. Total biomass of intercropped peanut increased owing to increased root growth. Across two years, yield of peanut intercropped with corn was 27.7% and with millet 32.8% higher than those of controls. Defoliation of cereal crops did not affect corn yield but significantly decreased millet yield by 24.5%. Our results suggest that applying seedling defoliation in intercropped corn could increase peanut yield without compromising corn yield in an intercropping system.

Intercropping of Peanut-Tea Enhances Soil Enzymatic Activity and Soil Nutrient Status at Different Soil Profiles in Subtropical Southern China.

Intercropping is one of the most widely used agroforestry techniques, reducing the harmful impacts of external inputs such as fertilizers. It also controls soil erosion, increases soil nutrients availability, and reduces weed growth. In this study, the intercropping of peanut (Arachishypogaea L.) was done with tea plants (Camellia oleifera), and it was compared with the mono-cropping of tea and peanut. Soil health and fertility were examined by analyzing the variability in soil enzymatic activity and soil nutrients availability at different soil depths (0–10 cm, 10–20 cm, 20–30 cm, and 30–40 cm). Results showed that the peanut–tea intercropping considerably impacted the soil organic carbon (SOC), soil nutrient availability, and soil enzymatic responses at different soil depths. The activity of protease, sucrase, and acid phosphatase was higher in intercropping, while the activity of urease and catalase was higher in peanut monoculture. In intercropping, total phosphorus (TP) was 14.2%, 34.2%, 77.7%, 61.9%; total potassium (TK) was 13.4%, 20%, 27.4%, 20%; available phosphorus (AP) was 52.9%, 26.56%, 61.1%; 146.15% and available potassium (AK) was 11.1%, 43.06%, 46.79% higher than the mono-cropping of tea in respective soil layers. Additionally, available nitrogen (AN) was 51.78%, 5.92%, and 15.32% lower in the 10–20 cm, 20–30 cm, and 30–40 cm layers of the intercropping system than in the mono-cropping system of peanut. Moreover, the soil enzymatic activity was significantly correlated with SOC and total nitrogen (TN) content across all soil depths and cropping systems. The depth and path analysis effect revealed that SOC directly affected sucrase, protease, urease, and catalase enzymes in an intercropping system. It was concluded that an increase in the soil enzymatic activity in the intercropping pattern improved the reaction rate at which organic matter decomposed and released nutrients into the soil environment. Enzyme activity in the decomposition process plays a vital role in forest soil morphology and function. For efficient land use in the cropping system, it is necessary to develop coherent agroforestry practices. The results in this study revealed that intercropping certainly enhance soil nutrients status and positively impacts soil conservation.

Development of Boyolali local peanut and composite corn planting patterns on rainfed rice fields

The location of the experiment was in the agro-ecosystem rainfed ricefield, Nogosari, Boyolali from June 2017 to September 2017. The research consisted of a survey of technology components commonly applied at the farmer level as well as demonstration plots of technology components in accordance with the integrated crop management of palawija (composite corn and local peanuts). Farmers’ understanding of the cultivation technology of peanuts and corn were very high. The yield of ubinan of Boyolali local peanut monoculture was still higher in farmer dosage (7.5 tons / ha) compared to the recommendation from Center for Agricultural Technology Studies (CATS) of Central Java. The yield of local peanut intercropping composite corn was higher (6.1 ton / ha) compared to the recommendation of CATS (5.0 ton / ha). The yield of monoculture corn cropping is 3.6 tones / ha at recommended dosage treatment and Provit A variety is 4 tons / ha. Meanwhile, the yield of corn in intercropping was experiencing crop failure. Thus, the intercropping pattern of peanuts and composite corn can be accepted by farmers and can develop in this area if assisted by dissemination in the form of demonstration plots in rainfed agro-ecosystems ricefield.

Effect of peanut intercropping and mycorrhiza in increasing yield of sweet corn yield

Many researchers reported that mycorrhizal symbiosis could significantly increase crop yield. The objective of this research was to examine the effects of mycorrhiza and intercropping with two peanut varieties on growth and yield of sweet corn. The experiment was conducted following paddy rice crop in Dasan Tebu, West Lombok, Indonesia, in the dry season 2018 and designed according to Split Plot design with four replications and two treatment factors, i.e. application of mycorrhiza-based biofertilizer as the main plots (M0 = without and M1=with mycorrhiza) and intercropping with peanut as the subplots (T0 = without intercropping, T1 = intercropping with peanut var. “Kelinci”, and T2 = intercropping with peanut var. “Bison”). The sweet corn cobs were harvested at the dough maturity stage. Results indicated that application of biofertilizer significantly increased stover dry weight, cob fresh weight, and number of green leaves per plant at harvest. Intercropping with peanuts also affected those observation variables and the height of ear position in the stem, and the “Bison” peanut variety was better than “Kelinci”. Although showing no significant interaction, intercropping with “Bison” did show higher benefits of biofertilization on both dry stover and fresh sweet corn cob weights than those with “Kelinci” variety.

The importance of aboveground and belowground interspecific interactions in determining crop growth and advantages of peanut/maize intercropping

Intercropping of maize (Zea mays L.) and peanut (Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific interactions between maize and peanut in field. A two-year field experiment was conducted to investigate the effects of interspecific interactions on plant growth and grain yield for a peanut/maize intercropping system under different nitrogen (N) and phosphorus (P) levels. The method of root separation was employed to differentiate belowground from aboveground interspecific interactions. We observed that the global interspecific interaction effect on the shoot biomass of the intercropping system decreased with the coexistence period, and belowground interaction contributed more than aboveground interaction to advantages of the intercropping in terms of shoot biomass and grain yield. There was a positive effect from aboveground and belowground interspecific interactions on crop plant growth in the intercropping system, except that aboveground interaction had a negative effect on peanut during the late coexistence period. The advantage of intercropping on grain came mainly from increased maize yield (means 95%) due to aboveground interspecific competition for light and belowground interaction (61%–72% vs. 28%–39% in fertilizer treatments). There was a negative effect on grain yield from aboveground interaction for peanut, but belowground interspecific interaction positively affected peanut grain yield. The supply of N, P, or N + P increased grain yield of intercropped maize and the contribution from aboveground interspecific interaction. Our study suggests that the advantages of peanut/maize intercropping for yield mainly comes from aboveground interspecific competition for maize and belowground interspecific facilitation for peanut, and their respective yield can be enhanced by N and P. These findings are important for managing the intercropping system and optimizing the benefits from using this system.

Maize plant density affects yield, growth and source-sink relationship of crops in maize/peanut intercropping

Abstract 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.

Border-row proportion determines strength of interspecific interactions and crop yields in maize/peanut strip 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.

Cassava/peanut intercropping improves soil quality via rhizospheric microbes increased available nitrogen contents

BackgroundIntercropping, an essential cultivation pattern in modern agricultural systems, increases crop yields and soil quality. Cassava and peanut intercropping systems exhibit advantages in solar utilization and cadmium absorption, etc. However, the inner mechanisms need to be elucidated. In this study, Illumina MiSeq platform was used to reveal the rhizospheric microbes and soil quality in cassava/peanut intercropping systems, and the results provided a reference for the application of this method in studying other intercropping systems.ResultsBoth intercropping cassava/peanut (IP) and intercropping peanut/cassava (IC) systems significantly increased available N, available K, pH value, and urease activity, comparing with that in monocropping cassava (MC) and monocropping peanut (MP) system. However, there were few effects on the total N, total P, total K, available P, organic matter, protease activity, catalase activity, sucrase activity, and acid phosphatase activity. Both IP and MP soils contained more bacteria and fungi than those in the IC and MC soils, which were mainly made of Proteobacteria and Actinobacteria. Intercropping remarkably increased the number of Nitrospirae in IP and IC soils comparing those in MC and MP soils. Redundancy analysis (RDA) revealed that the abundances of DA101, Pilimelia, and Ramlibacter were positively correlated to the soil quality. These results suggest that intercropping enhances the available nitrogen content of soil through increasing the quantity of rhizospheric microbes, especially that of DA101 and Pilimelia.ConclusionsThe cassava/peanut intercropping system improves soil quality through increasing the available nitrogen content and abundance of DA101, Pilimelia, and Ramlibacter in the soil.

Wide-strip intercropping of cotton and peanut combined with strip rotation increases crop productivity and economic returns

Cotton/peanut intercropping and their rotation have been widely studied and adopted in many cotton and peanut growing countries including China. However, it is impossible to harvest two crops in the same year under the cotton/peanut rotation. And continuous cropping constraints as indicated by inhibited crop growth and development as well as yield decline remain under continuous cotton/peanut intercropping. We hypothesized that a combination of intercropping and rotation can resolve these constraints or challenges. In a preliminary experiment, the traditional intercropping (TIC) of cotton and peanut was established and studied using monocultures of cotton (MC) or peanut (MP) as the control. Field experiments were then conducted to develop an alternate intercropping (AIC) of wide-strip cotton/peanut intercropping in combination with strip rotation (strips of the two crops were grown inter-annually in an alternate manner). Crop productivity, leaf photosynthesis, dry matter accumulation and partitioning, and main nutrient uptake as well as input-output and net returns of the new system were evaluated as compared with TIC, MC and MP for two consecutive years. Results showed that crop productivity varied significantly with cropping systems. On average, the TIC increased seed cotton yield by 16.9% and decreased peanut yield by 5.6%, while the AIC increased cotton yield by 21% without sacrificing peanut yield. The AIC increased the biological yield of peanut by 3.8% and harvest index by 2.4%; it increased the biological yield of cotton by 3.8% compared to TIC. AIC increased uptake of N, P and K in peanut by 6.3, 11.5 and 7.3%, as well as net photosynthetic rate, chlorophyll content and maximum leaf area index of peanut by 7.2, 8.9 and 4.4%, respectively, relative to TIC. Crop output value under AIC was 4.5% higher than that under TIC but the input value was the same; thus the net return under AIC exceeded that under TIC by 10%. The AIC increased crop productivity and economic return without additional input compared to traditional intercropping, thus is a promising alternative cropping system in the Yellow River valley and other areas with similar ecology.

Reducing Nitrogen and Phosphorus Losses from Different Crop Types in the Water Source Area of the Danjiang River, China.

Nitrogen and phosphorus are essential for plant growth and are the primary limiting nutrient elements. The loss of nitrogen and phosphorus in agricultural systems can cause the eutrophication of natural water bodies. In this paper, a field simulated rainfall experiment was conducted in a typical small watershed of the Danjiang River to study the nutrient loss process of nitrogen and phosphorus in slope croplands subjected to different crops and tillage measures. The characteristics of the runoff process and nutrient migration of different slope treatments were studied, which were the bare-land (BL, as the control), peanut monoculture (PL), corn monoculture (CL), bare land (upper slope) mixed with peanut monoculture (lower slope) (BP), corn and peanut intercropping (TCP), corn and soybean intercropping (TCS), downslope ridge cultivation (BS) slope, and straw-mulched (SC), respectively. The results showed that the runoff of CL, SC, TCS, BS, BP, PL and TCP slope types were 93%, 75%, 51%, 39%, 28%, 12%, and 6% of the those of the bare land, respectively. The total nitrogen concentration in runoff on different slope types decreased in the order of BP > PL > BS > SC > TCP > BL > CL > TCS. The BL was characterized with the highest NRL-TN (the loss of total nitrogen per unit area), with the value of 1.188 kg/hm2, while those of the TCP is the smallest with the value of 0.073 kg/hm2. The total phosphorus concentration in runoff decreasd in the order of BS > BP > PL > BL > TCP > SC > CL > TCS. The PRL-TP (the loss of total phosphorus per unit area) of BL is the largest (0.016 kg/hm2), while those of TCP is the smallest (0.001 kg/hm2). These indicate that the loss of nitrogen is much higer than that of phosphorus. The loss of nitrogen in runoff is dominated by nitrate nitrogen, which accounts for 54.4%–78.9% of TN. Slope croplands in the water source area should adopt the tillage measures of TCP and PL.These measures can reduce 85% of the runoff of nitrogen and phosphorus compared to the bare land. The results may assist in agricultural non-point source pollution control and help promote improved management of the water environment in the Danjiang River’s water source area.

Effect of peanut (Arachis hypogaea L.)/cowpea (Vigna unquiculata L.) intercropping combined with organic mature application on soil microfauna

We studied the benefits of peanut (Arachis hypogaea L.) intercropping (I) or relaycropping (R) with cowpea (Vigna unquiculata L.) and fertilizer application rates (unfertilized control, N; chemical fertilizer, C; organic manure, O; 50% C + 50% O, H) on soil biological properties of an Udic Mollisol. The crop multiple cropping and peanut monocropping (M) were established in 2002 and fertilizer was applied to any plots. We hypothesize that peanut/cowpea multiple cropping harbour a greater microfauna diversity, while organic mature application support a more complex soil food web and soil functioning. Combined the two factors implies a beneficial soil ecosystem for peanut production via repelling PPNs. The results showed microbial C and N over the growing season were 39.2% and 30.7% greater when peanut was intercropped and relaycropped than in monocropping plots. Total organic C, total N and alkali hydrolysable N were average 24.6%–43.1% greater when organic manure was applied than in the chemical fertilizer plots. Soil nematode community in peanut monocropping was dominated by plant parasites, mainly from Meloidogyne spp., but their abundance decreased when cowpea was associated to peanut. The cowpea also impacted other trophic groups. The proportion of bacterivores and high colonizer-persister (c-p) value omnivore-carnivores was increased in multi-cropping plots. The abundance of protozoa and fungivores were 36.9% and 29.8% greater in mixed manure plots than in no fertilization plots at flowering stage. The increased diversity indices (H′) and ecological indices (EI and SI) of the nematode communities indicated less disturbance and high soil fertility in multiple cropping systems. Overall, peanut multi-cropping with manure had a positive effect on peanut rhizosphere soil conditions.

Investigation of Runoff and Sediment Yields Under Different Crop and Tillage Conditions by Field Artificial Rainfall Experiments

Crop types and tillage measures on slopes have significant impacts on regional water and soil conservation. In this study, we investigated the influences of multiple crop types and tillage measures on water and sediment yields based on plot-scale experiments under artificial rainfall. The objective of the study is to find the best combination of crop type and tillage measure from the perspective of reducing soil erosion. We performed artificial rainfall experiments under eight slope treatments, which are the bare-land (BL, as a reference), peanut monoculture (PL), corn monoculture (CL), bare land (upper slope) mixed with peanut monoculture (lower slope) (BP), corn and peanut intercropping (TCP), corn and soybean intercropping (TCS), downslope ridge cultivation (BS) slope, and straw-mulched (SC), respectively. Under similar rainfall intensity and initial soil moisture conditions, these treatments except for BS efficiently reduced sediment yield compared to the BL slope. In comparison, the most effective slope treatment to reduce soil erosion is TCP, followed by PL and TCS. The amount of sediment yielded from the three treatments accounts for 0.4%, 2.0%, and 3.3% of the sediment yielded from BL. We recommend the three slope treatments as the preferred choices among eight treatments. Also, the lower sediment yield in the three slope treatments benefits from their higher vegetation coverage. Vegetation coverage plays a greater role in regulating sediment yield than the surface runoff at a plot scale.

Physiological and molecular mechanisms of improved iron nutrition of peanut intercropping with maize

Intercropping is one of the most important farming practices for efficient use of farmland ecosystems and sustainable yield productions. Peanut intercropped with maize could significantly reduce peanut chlorosis symptom and increase the plant iron (Fe) content and crop yield in the North China Plain. The physiological and molecular mechanisms behind this phenomenon have been extensively studied for decades. Peanut and maize have evolved two distinct mechanisms in response to Fe deficiency, known as “the Strategy I” and “the Strategy II”, respectively. The Strategy I plants take up Fe2+ through soil acidification and Fe3+ reduction, while the Strategy II plants acquire Fe via secreting mugineic acid family phytosiderophores (MAs) to dissolve insoluble ferric Fe and to form absorbable Fe(III)–MAs complexes in the rhizosphere. At the molecular level, key genes involved in Fe acquisition have been well characterized. In the Strategy I plants, peanut ferric reductase oxidase2 (AhFRO2) and iron regulated transporter1 (AhIRT1) are responsible for the reduction of Fe(III)-chelate to Fe(II) and the uptake of Fe(II), respectively. In the Strategy II plants, MAs are synthesized from methionine and secreted by mugineic acid transporter1 (MA1). The secreted MAs solubilize Fe in the rhizosphere and the resultant Fe(III)-MAs complex is then absorbed by the yellow stripe1 (YS1) transporter in maize. As a result, the Strategy II maize is more effective at mobilizing precipitated Fe, less affected by high pH and bicarbonate levels, and having a much stronger ability to resist Fe-limitation stress in calcareous soils compared with Strategy I peanuts. However, the Fe-limitation stress in peanuts could be alleviated when intercropping with maize. At physiological and biochemical levels, the ecological advantages of rhizosphere interaction is to significantly enhance the absorption and transport of Fe by intercropped peanut roots and to validate the functions of genes involved. In particular, it has been demonstrated that the AhYSL1 gene which is expressed in the peanut root epidermal cells can specifically regulate the absorption of the Fe(III)–DMA compound. Peanuts could directly absorb Fe(III)-DMA from the rhizosphere of intercropped maize. The intercropping of maize and peanut with different Fe absorption mechanisms not only improves peanut Fe nutrition but also increases resistance of these two crops. In addition, higher accumulation of photosynthesis-related proteins in intercropped peanut leaves suggests that the intercropped peanuts have a higher photosynthetic efficiency. Moreover, stress-responsive proteins displayed elevated expression levels in both peanut and maize in a monocropping system. This suggests that intercropping contributes to resistance to stress conditions. Intercropping also enhances jasmonate signaling and weakens ethylene signaling in peanut and maize roots, which may improve ecological adaptation of the maize and peanut plants in the intercropping system. The advantage in ecology system makes maize/peanut intercropping as a typical model of “bio-fortification”. The nutrient benefit of the inter-rhizosphere regulatory measure can be an important technological measure for bio-fortification to improve human health and nutrition. The research on the mechanisms underlying the beneficial effects of maize/peanut intercropping could provide important theoretical and applied bases to understand and utilize the reciprocal effect of different plant biological characteristics and to improve rhizosphere ecological environments, crop iron nutrition and efficient utilization of resources.

Combination urea and compost fertilizer with different defoliation affected corn and peanut production based on integrated farming system

This research was aimed to study the effect of combination of compost and urea fertilizer, leaf defoliation intercropping system of corn and peanut crop. This study was conducted for 4 months and designed by Separate Plot Design. Defoliation of leaves under cob is main plot and combination of urea and compost doses is subplot. The treatments are as follows; main plot d0 = Without defoliation (control); d1 = 50% Defoliation; d2 = 100% Defoliation and combination of Urea and Compost doses; Subplot; p0 = 250 kg Urea/ha + 3 tons of compost/ha; p1 = 230 kg Urea/ha + 6 tons of compost/ha p2 = 210 kg Urea/ha + 9 tons of compost/ha; p3 = 190 kg Urea/ha + 12 tons of compost/ha. Each combination is repeated three times so that the total number is 36 plot experiments. Data were analyzed by using variance analysis and analysis of continuation test of least significance different (LSD). The results showed that the combination of fertilization is the same dry shelled corn production and dry peanut. d1 treatment and its interaction could increase dry production of shelled corn and peanut. Intercropping of corn and peanut is feasible to be cultivated in an integrated farming system.

Yield response of upland Rice + Peanut intercropping schemes to Rhizobial (Bio-N) inoculation

Yield response of upland Rice + Peanut intercropping schemes to Rhizobial (Bio-N) inoculation

Variation of Fine Roots Distribution in Apple (Malus pumila M.)–Crop Intercropping Systems on the Loess Plateau of China

In arid and semi-arid areas, interspecific below-ground competition is prominent in agroforestry systems. To provide theoretical and technical guidance for the scientific management of apple–crop intercropping systems, a field study was conducted in the Loess Plateau of China to examine the variation of fine roots distribution in apple–crop intercropping systems. The fine roots of apple trees and crops (soybean (Glycine max (L.) Merr) or peanuts (Arachis hypogaea Linn.)) were sampled to 100 cm depth at ten distances from the tree row using the stratified excavation method. The results showed that the vertical distribution of fine roots between intercropped apple trees and intercropped crops were skewed and overlapped. Apple–crop intercropping inhibited the fine roots of apple trees in the 0–60 cm soil depth, but promoted their growth in the 60–100 cm soil depth. However, apple–crop intercropping inhibited the fine roots of intercropped crops in the 0–100 cm soil depth. For the fine roots of each component of the apple–crop intercropping systems, variation in the vertical distribution was much greater than variation in the horizontal distribution. Compared with monocropped systems, apple–crop intercropping caused the fine roots of intercropped apple trees to move to deeper soil, and those of intercropped crops to move to shallower soil. Additionally, apple–crop intercropping slightly inhibited the horizontal extension of the fine-root horizontal barycentre (FRHB) of intercropped apple trees and caused the FRHB of intercropped crops to be slightly biased towards the north of the apple tree row. Variation of the fine roots distribution of each component of the apple–soybean intercropping system was greater than that of the apple–peanut intercropping system. Thus, the interspecific below-ground competition of the apple–peanut intercropping system was weaker than that of the apple–soybean intercropping system. Intense competition occurred in the apple–peanut intercropping system and the apple–soybean intercropping system was in sections whose distance ranged from 0.5–1.3 and 0.5–1.7 m from the tree row, respectively. The interspecific below-ground competition was fiercer on the south side of the apple tree row than on the north side.