Assessing the Efficacy of Wheat-Soybean Based Intercropping System at Different Plant Densities in Bambili, Cameroon

Wheat is one of the most important cereals in the world, serving as a staple for millions globally. In the wake of the geopolitical crisis between Russia and Ukraine, it has become incumbent for many countries to invest in wheat production. Improving cropping systems for wheat production is paramount. Intercropping cereals with legumes has tremendous advantages. Therefore, this study was designed to optimize wheat production by intercropping it with soybean at different densities. Between March and August 2023, a randomized complete block design trial was conducted in Bambili, North West of Cameroon with treatments T1 (wheat monocrop at 200,000 plants ha−1), T2 (soybean monocrop at 250,000 plants ha−1), T3 (200,000 wheat and 125,000 soybean ha−1), T4 (100,000 wheat and 250,000 soybean ha−1), T5 (200,000 wheat and 250,000 soybean ha−1) and T6 (100,000 wheat and 125,000 soybean ha−1). Results revealed that growth parameters of wheat were not significantly influenced by monocrop or intercrop. The yield of wheat was significantly higher in the monocrop than the intercrop treatments, with slight variation amongst the intercrop treatments. Soybean yield was higher in the monocrop than in the intercrop, with no variations amongst the intercrop treatments. Only the land equivalence ratio (LER) for T5 was greater than 1.0. The competitive ratio for T5 was 0.54 for wheat and 1.90 for soybean, comparatively lower than the other monocrop treatments. Intercropping wheat and soybean at 200,000:250,000 ratio is recommended.

Several Cotton Rotation and Intercropping Systems in Cotton Planting Area of Eastern Henan Province

In recent years,the area dedicated to cotton cultivation in eastern Henan Province has experienced a continuous decline.Developing efficient multi-cropping systems for cotton and increasing the multiple cropping index represent effective strategies to stabilize the cotton planting area and enhance the income of cotton farmers.This paper presents an overview of intercropping systems and the benefits associated with cotton rotation and intercropping practices.Specifically,it discusses the"early maturing cotton-wheat"rotation system,the"cotton-watermelon"intercropping system,the"cotton-Dutch bean"intercropping system,and the"early maturing cotton-peanut-garlic"intercropping system.

Assessment of Nitrogen Fixation, Uptake, and Leaching in Maize/Soybean Intercropping System at Varied Soil Depths and under Phosphorus Application in Chinese Agricultural Settings

The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducted in Quzhou, Hebei Province, China, with MC812 maize and Jidou12 soybean varieties. Soil samples were taken from each plot to create a composite sample. The results show that nitrogen concentration varies at different depths and is higher in all treatments between 40 and 100 cm. Incorporating intercropping of maize and soybeans into farming practices can lead to more sustainable and environmentally friendly agriculture in China.

Influence of Fruit Tree Types and Arrangements on Yield, Quality and Economic Returns of Cotton of Intercropping System in Southern Xinjiang

[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows： under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows： jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.

Highly-efficient Intercropping Mode and Selection of Suitable Peanut Varieties in Maize and Peanut Intercropping Systems

[Objective] The aim was to explore efficient maize and peanut intercrop-ping mode and select suitable peanut varieties of the mode in Yungui Plateau. [Method] In the test, 6 cropping methods were set by randomized block design. Yields and economic benefits were measured in mature stage with Excelland DPS. [Result] Compared with monoculture, maize and peanut intercropping systems took advantages and LER values were proved higher than 1. In the intercropping system with maize and Yun peanut No.3 at 2∶2, in particular, the value of LER was 1.40 and compound yield reached 9 036 kg/hm2; the net output values of maize kernel and fresh/dry peanut pod increased by 182.63% and 140.59%, compared with maize by monoculture. In addition, the output values of Yun peanut No.3 by monoculture and intercropping system increased by 5 069 and 3 272 yuan/hm2, respectively, than Yanshan conventional peanut varieties. [Conclusion] The efficient intercropping system with maize and peanut mode at 2∶2 mode in Yungui plateau and the Yun peanut No.3 exhibited higher yield and economic benefit advantages, compared with Yanshan conventional planting peanut varieties.

Effects of Sowing Rate on Marginal Superiority and Yield of Wheat in Wheat-cotton Intercropping System

In the wheat-cotton intercropping system, total 6 sowing rates （187.5, 225.0, 262.5, 300.0, 337.5 and 375.0 kg/hm2） were arranged, and the effects of sowing rate on marginal superiority and yield of wheat were investigated. The re- sults showed that the effect of sowing rate on inner-line wheat was greater than that on side-line wheat; with the increased sowing rate, the marginal superiority of panicle number was reduced in overall, and the difference in panicle number be- tween inner and side lines was decreased from 9.0×10^5/hm2 （sowing rate of 187.5 kg/hm2） to 7.8×10^5/hm2 （sowing rate of 375.0 kg/hm2）; the marginal superiority of grains per spike was increased first and then reduced, and the largest difference in grains per spike between the inner and side lines reached 4.6 under the sowing rate of 300.0 kg/hm2; the marginal superiority of 1 000-grain weight and yield was gradually increased, and the largest difference in 1 000-grain weight between the inner and side lines reached 3.9 g under the sowing rate of 337.5 kg/hm2, and in yield reached 3 136.5 kg/hm2under the sowing rate of 375.0 kg/hm2. The effects of sowing rate on the three yield factors of intercropped wheat ranked as panicle number 〉 grains per spike 〉 1 000-grain weight. The appropriate sowing rate of wheat was 225.0-262.0 kg/hm2 in the wheat-cotton intercropping system.

Effects of N,P and K Amounts on Yield Traits of Wheat in Wheat-cotton Intercropping System

[Objective] This study was conducted to investigate the demands for N, P and K by wheat in wheat cotton intercropping system in high-fertility field of Hebei Province. [Method] The experiment adopted randomized block arrangement. Five treatments （0, 75, 150, 225 and 300 kg/hm2） were designed for N, P and K. Wheat tillering, ear number, yield and yield components were investigated. [Result] Wheat yield increased significantly with the application of N fertilizer. The number of ears per unit area, number of grains per ear, 1 000-grain weight and yield were im- proved with N increasing. P fertilizer improved wheat yield at a certain degree, but K had no effect on wheat yield. ]Conclusion] The optimum fertilization for wheat-cot- ton intercropping system was N at 225-300 kg/hm2 and P2Os at 150 kg/hm2; and there is no need to apply K.

Analysis on Marginal Superiority and Yield of Different Wheat Varieties in Wheat-cotton Intercropping System

In wheat-cotton intercropping system,the spike number per unit area,grains per spike,thousand-grain weight and yield of side line and inner line were investigated in six wheat varieties to study the marginal superiority and select suitable wheat varieties intercropped with cotton.The results showed that Xingmai No.4had obvious marginal superiority with the yield of 6 919.0 kg/hm2,so it was the suitable variety for wheat-cotton intercropping system.

Study on Yield Potential of Autumn Potato/Rapeseed Intercropping System in Rice Field

In order to expIore the yield potential, regional adaptabiIity and key cuItiva-tion techniques of autumn potato/rapeseed intercropping system, and analyze its benefit performance and popuIarization value, the contrast experiments of Iarge re-gion were conducted in Yongchuan and Kalxian of Chongqing city from 2011 to 2012. The resuIts showed that the benefit increasing effect was significant because autumn potato/rapeseed intercropping patterns couId galn more one season potato in rice-rapeseed rotation area. The average yield of autumn potato and rapeseed in two test points were 13 567.35 and 2 663.25 kg/hm2 respectiveIy, and the total out-put value and net income reached to 38 773.05 yuan/hm2 and 15 772.5 yuan/hm2 respectiveIy, and cash income attalned 38 773.05 yuan/hm2, and net income reached 23 000.55 yuan/hm2, and the increased income was 17 221.8 yuan/hm2 and it increased by 310.3% comparing with rapeseed of soIe cropping. Therefore, the autumn potato/rapeseed intercropping in rice field is a new efficient cuItivation technique with very significant ecoIogical and economic benefit.

Nitrate Leaching from Maize Intercropping Systems with N Fertilizer Over-Dose

A 2-yr field experiment was conducted on a calcareous alluvial soil with four summer maize intercropping systems at Shangzhuang Experiment Station （116.3°E, 39.9°N） in the North China Plain. The objective was to determine nitrate leaching from intercropping systems involving maize （Zea mays L.）： sole maize （CK）, maize ＋ soybean （CST）, maize ＋ groundnut （CGT）, maize ＋ ryegrass （CHM）, and maize ＋ alfalfa （CMX）. Intercropping greatly reduced nitrate accumulation in the 100-200 cm soil layers compared with maize monoculture. Nitrate accumulation under intercropping systems decreased significantly at the 140-200 cm soil depth; the accumulation varied in the order CK〉CST〉CMX〉CHM〉CGT. However, compared to the CK treatment, nitrate leaching losses during the maize growing period were reduced by 20.9- 174.8 （CGT）, 35.2-130.8 （CHM）, 60.4-122.0 （CMX）, and 30.6-82.4 kg ha-1 （CST）. The results also suggested that intereropping is an effective way to reduce nitrogen leaching in fields with N fertilizer over-dose.

Optimized nitrogen application methods to improve nitrogen use efficiency and nodule nitrogen fixation in a maize-soybean relay intercropping system

In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system （IMS）. Three N rates, NN （no nitrogen application）, LN （lower N application： 270 kg N ha-1）, and CN （conventional N application： 330 kg N ha-1）, and three topdressing distances of LN （LND）, e.g., 15 cm （LND1）, 30 cm （LND2） and 45 cm （LND3） from maize rows were evaluated. At the beginning seed stage （R5）, the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant-1 and 0.14 mL h-1 plant-1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency （NAE） of IMS under CN were 308.3 kg ha-1, 28.5%, and 5.7 kg grain kg-1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15-30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.

Soil Nitrous Oxide Emissions Under Maize-Legume Intercropping System in the North China Plain

Many studies have focused on various agricultural management measures to reduce agricultural nitrous oxide （N2O） emission. However, few studies have investigated soil N2O emissions in intercropping systems in the North China Plain. Thus, we conducted a ifeld experiment to compare N2O emissions under monoculture and maize-legume intercropping systems. In 2010, ifve treatments, including monocultured maize （M）, maize-peanut （MP）, maize-alfalfa （MA）, maize-soybean （MS）, and maize-sweet clover （MSC） intercropping were designed to investigate this issue using the static chamber technique. In 2011, M, MP, and MS remained, and monocultured peanuts （P） and soybean （S） were added to the trial. The results showed that total production of N2O from different treatments ranged from （0.87＆#177;0.12） to （1.17＆#177;0.11） kg ha-1 in 2010, while those ranged from （3.35＆#177;0.30） to （9.10＆#177;2.09） kg ha-1 in 2011. MA and MSC had no signiifcant effect on soil N2O production compared to that of M （P＆lt;0.05）. Cumulative N2O emissions from MP in 2010 were signiifcantly lower than those from M, but the result was the opposite in 2011 （P＆lt;0.05）. MS signiifcantly reduced soil N2O emissions by 25.55 and 48.84%in 2010 and 2011, respectively （P＆lt;0.05）. Soil N2O emissions were signiifcantly correlated with soil water content, soil temperature, nitriifcation potential, soil NH4＋, and soil NO3-content （R2=0.160-0.764, P＆lt;0.01）. A stepwise linear regression analysis indicated that soil N2O release was mainly controlled by the interaction between soil moisture and soil NO3-content （R2=0.828, P＆lt;0.001）. These results indicate that MS had a coincident effect on soil N2O lfux and signiifcantly reduced soil N2O production compared to that of M over two growing seasons.

Timing and splitting of nitrogen fertilizer supply to increase crop yield and efficiency of nitrogen utilization in a wheat–peanut relay intercropping system in China

Agronomically optimizing the timing and rates of nitrogen(N) fertilizer application can increase crop yield and decrease N loss to the environment. Wheat(Triticum aestivum L.)–peanut(Arachis hypogaea L.) relay intercropping systems are a mainstay of economic and food security in China. We performed a field experiment to investigate the effects of N fertilizer on N recovery efficiency, crop yield, and N loss rate in wheat–peanut relay intercropping systems in the Huang-Huai-Hai Plain, China during 2015–2017. The N was applied on the day before sowing, the jointing stage(G30) or the booting stage(G40) of winter wheat, and the anthesis stage(R1) of peanut in the following percentage splits: 50-50-0-0(N1), 35-35-0-30(N2), and 35-0-35-30(N3), using 300 kg N ha-1, with 0 kg N ha-1(N0) as control. ^(15)N-labeled(20.14 atom %) urea was used to trace the fate of N in microplots. The yields of wheat and peanut increased by 12.4% and 15.4% under the N2 and N3 treatments, relative to those under the N1 treatment. The ^(15)N recovery efficiencies( ^(15)NRE) were 64.9% and 58.1% for treatments N2 and N3, significantly greater than that for the N1 treatment(45.3%). The potential N loss rates for the treatments N2 and N3 were23.7% and 7.0%, significantly lower than that for treatment N1(30.1%). Withholding N supply until the booting stage(N3) did not reduce the wheat grain yield; however, it increased the N content derived from ^(15)N-labeled urea in peanuts, promoted the distribution of ^(15)N to pods, and ultimately increased pod yields in comparison with those obtained by topdressing N at jointing stage(N2). In comparison with N2, the N uptake and N recovery efficiency(NRE) of N3 was increased by 12.0% and 24.1%,respectively, while the apparent N loss decreased by 16.7%. In conclusion, applying N fertilizer with three splits and delaying topdressing fertilization until G40 of winter wheat increased total grain yields and NRE and reduced N loss. This practice could be an environment-friendly N management strategy for wheat–peanut relay intercropping systems in China.

Effect of Inoculation with Arbuscular Mycorrhizal Fungus on Nitrogen and Phosphorus Utilization in Upland Rice-Mungbean Intercropping System

The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF colonization rates of rice and mungbean roots, plant nutrient contents, the ability of nitrogen fixation, and nutrient contents changed in the soil were analyzed. The results were obtained as follows： the rates of AMF colonization of rice and mungbean roots were reached to 14.47 and 92.2% in intercopping system, and increased by 4.11 and 11.95% compared with that of in monocropping; the nirtrogen contents of mungbean and rice were increased by 83.72 and 64.83% in shoots, and 53.76 and 41.29% in roots, respectively, while the contents of iron in shoot and root of mungbean were increased by 223.08 and 60.19%, respectively. In the intercropping system with inoculation of AMF, the biomass of mungbean increased by 288.8%. However, the biomass of rice was not significantly changed among all treatments with or without inoculation of AMF recorded. The number and dry weight of nodules were significantly increased either when mungbean was intercropped with rice or inoculated with AMF. When compared with that of monocropping without AMF inoculation, the contents of nitrogen, phosphorus and iron in nodules of intercropping mungbean with inoculation increased by 80.14, 69.54 and 39.62%, respectively. Additionally, intercropping with AMF inoculation significantly increased soil nitrogen content, but reduced soil phosphorus content. We concluded that upland rice-mungbean intercropping system and inoculation with AMF improved the nutrient uptake, the ability of nitrogen fixation and the growth of mungbean.

Plant Phosphorus Uptake in a Soybean-Citrus Intercropping System in the Red Soil Hilly Region of South China

A field microplot experiment was conducted in the red soil hilly region of South China to evaluate plant phosphorus (P)uptake under soybean and citrus monoculture and the soybean-citrus intercropping system using the 32P tracer technique.P fertilizer was applied at three depths(15,35,and 55 cm).The experimental results showed that the planting pattern and 32P application depth significantly affected the characteristics of P uptake by soybean and citrus.Under the soybean-citrus intercropping system,considerable competition was observed when the 32P fertilizer was applied to the topsoil(15 cm);therefore,the 32P recovery rate declined by 41.5%and 14.7%for soybean and citrus,and 32P supplying amount of topsoil to soybean and citrus decreased by 346.8 and 148.1 mg plot-1,respectively,compared to those under the monoculture.However,32P recovery of soybean was promoted when 32P fertilizer was applied to the deeper soil layers (35 and 55 cm)under soybean-citrus intercropping.Under the soybean monoculture,32P fertilizer could hardly be used by soybean when 32P fertilizer was applied at the 55 cm depth or below,with the recovery rate being less than 0.1%;it was up to 0.253%by soybean under intercropping.The higher P recovery of soybean under soybean-citrus intercropping when P was applied in the deeper soil layers was because part of the P nutrient that the citrus absorbed from the deeper soil layers could be released into the topsoil and then it could be used by the soybean.

Effects of intercropping systems of trees with soybean on soil physicochemical properties in juvenile plantations

The intercropping system of tree with soybean in juvenile plantations, as a short-term practice, was applied at Lao Shan Experimental Station in Mao＇er Shan Forest of Northeast Forestry University, Harbin, China. The larch （Larix gmelinii）lsoybean （Glycine max.） and ash （Fraxinus mandshurica） intercropping systems were studied in the field to assess the effects of the intercropping on soil physicochemical properties. The results showed that soil physical properties were improved after soybean intercropping with larch and ash in one growing season. The soil bulk density in larch/soybean and ash/soybean systems was 1.112 g·cm^-3 and 1.058 g·cm^ 3, respectively, which was lower than that in the pure larch or ash plantation without intercropping. The total soil porosity also increased after intercropping. The organic matter amount in larch/soybean system was 1.77 times higher than that in the pure larch plantation, and it was 1.09 times higher in ash/soybean system than that in the pure ash plantation. Contents of total nitrogen and hydrolyzable nitrogen in larch/soybean system were 4.2% and 53.0% higher than those in the pure larch stand. Total nitrogen and hydrolyzable nitrogen contents in ash/soybean system were 75.5% and 3.3% higher than those in the pure ash plantation. Total phosphorus content decreased after intercropping, while change of available phosphorus showed an increasing trend. Total potassium and available potassium contents in the larch/soybean system were 0.6% and 17.5% higher than those in the pure larch stand. Total potassium and available potassium contents in the ash/soybean system were 56.4% and 21.8% higher than those in the oure ash plantation.

Shade adaptive response and yield analysis of different soybean genotypes in relay intercropping systems

Soybean is one of the major oil seed crops,which is usually intercropped with other crops to increase soybean production area and yield.However,soybean is highly sensitive to shading.It is unclear if soybean morphology responds to shading（i.e.,shade tolerance or avoidance）and which features may be suitable as screening materials in relay strip intercropping.Therefore,in this study,various agronomic characteristics of different soybean genotypes were analyzed under relay intercropping conditions.The soybean materials used in this study exhibited genetic diversity,and the coefficient of variations of the agronomic parameters ranged from 13.84 to 72.08%during the shade period and from 6.44 to 52.49%during the maturity period.The ratios of shading to full irradiance in stem mass fraction（SMF）were almost greater than 1,whereas opposite results were found in the leaves.Compared with full irradiance,the average stem length（SL）,leaf area ratio（LAR）and specific leaf area（SLA）for the two years（2013 and 2014）increased by 0.78,0.47 and 0.65 under shady conditions,respectively.However,the stem diameter（SD）,total biomass（TB）,leaf area（LA）,number of nodes（NN）on the main stem,and number of branches（BN）all decreased.During the shady period,the SL and SMF exhibited a significant negative correlation with yield,and the SD exhibited a significant positive correlation with yield.The correlation between the soybean yield and agronomic parameters during the mature period,except for SL,the first pod height（FPH）,100-seed weight（100-SW）,and reproductive growth period（RGP）,were significant（P〈0.01）,especially for seed weight per branch（SWB）,pods per plant（PP）,BN,and vegetative growth period（VGP）.These results provide an insight into screening the shade tolerance of soybean varieties and can be useful in targeted breeding programs of relay intercropped soybeans.

Boosting proso millet yield by altering canopy light distribution in proso millet/mung bean intercropping systems

To elucidate the mechanism by which intercropping proso millet(Panicum miliaceum L.)with mung bean(Vigna radiata L.)increases proso millet yield and to determine how this higher yield results from maximization of resources use efficiency,we designed and conducted four strip intercropping row arrangements,including two rows of proso millet alternating with two rows of mung bean(2P2M),four rows of proso millet alternating with two rows of mung bean(4P2M),four rows of proso millet alternating with four rows of mung bean(4P4M),two rows of proso millet alternating with four rows of mung bean(2P4M),sole proso millet(SP,control)and sole mung bean(SM,control)in Yulin,Shaanxi,China.Photosynthetically active radiation(PAR)in the canopy,radiation use efficiency(RUE),leaf photosynthetic characteristics,dry matter accumulation and allocation,and yield of proso millet were investigated.The results showed that the intercropping systems had higher PAR than the monoculture.Mean PAR intensities were increased by respectively 2.2%–23.4%,19.8%–59.7%,and 61.2%–133.3%in the proso millet upper,middle and lower canopies compared with SP.The increase in PAR directly increased RUE,a result attributed mainly to the increase in photosynthetic capacity,including net photosynthetic rate and chlorophyll content.These responses resulted in increased dry matter allocation to plant organs.Yield of intercropped proso millet was 6.8%–37.3%higher than that under monoculture and the land equivalent ratios for the different intercropping patterns were all greater than unity(>1).In general,yield followed a positive linear function of PAR in the intercropping system.The results indicated that intercropping can boost proso millet yield,evidently by altering light distribution within its canopy and consequently increasing RUE,thereby increasing leaf photosynthetic capacity,dry matter accumulation,and allocation to the grain.The optimum combination for improving the growth and yield of proso millet on the Loess Plateau of China was 2P4M.

Effects of Intercropping and Shading Systems on Tea Photosynthesis and Respiration

[Objective] The aim was to provide references for constructing compound ecological tea gardens. [Method] In an ecological adult-tea garden, teas shaded by Prunus cerasoides, Prunus L., and Litsea pungens were selected and the teas without shades were taken as a control in order to explore effects of tree shading on photosynthesis, respiration and net photosynthetic intensities. [Result] In a growth cycle of one year, for teas shaded by Prunus cerasoides, Prunus L., and Litsea pungens, respiration intensity was significantly higher than that of the control; net photosynthetic intensity was extremely significant higher; photosynthesis intensity showed none rules. Both of net photosynthetic rate and intensity kept higher in winter of shaded teas. [Conclusion] It is of significance for high-yielding and high-quality teas to reduce respiration consumption and coordinate between photosynthesis and respiration given that tea grows well.

The Ecological Effects of Young Elm Trees Belt-Pumpkin Strip Intercropping System at the Agro-Pastoral Ecotone in Northern China

Young elm trees belt-pumpkin strip intercropping was studied to solve the actual problem of resource losses in the large barren area resulted from reconverting cultivated land into forest in the agro-pastoral ecotone in northern China. The final objective was to realize effective utilization of the barren land with both ecological improvement and economic development. Field experiments were conducted together with laboratory analysis. The results indicated that the soil moisture level was remarkably increased in young elm trees belt-pumpkin strip intereropping because the pumpkin vines covered the gap between pumpkin planting-furrow and elm trees belt. The water use efficiency of the intercropping system was increased by 23.7-163.3% as compared with the single cropping. Elm trees belt-pumpkin strip intercropping changed the sequential succession trend of the grasses growing in the gap of the pumpkin planting-furrow. The annual grasses become the dominant vegetation. The nutritive value as fodder and yield of the annual grasses were also increased remarkably. The biomass of pumpkin, elm trees and grasses under intercropping increased by 24.4, 28.4 and 144.4%, respectively, as compared with those under single cropping. The land use efficiency was increased by 132%. It was also indicated that the soil erosion from the intercropping land was not increased due to pumpkin plantation. The differences in the soil erosion among intercropped area, elm trees belt and pumpkin strip with single cropping were not remarkable. Therefore, it was concluded that young elm trees belt-pumpkin strip intercropping is an effective way to utilize the barren land between the young elm trees belt and realize synergistic enhancement of ecological benefit and economic profit.