Alternate cotton-peanut intercropping:a new approach to increasing productivity and minimizing environmental impact

Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in the alternate cotton-peanut intercropping,specifically focusing on its yield benefits,environmental impacts,and the underlying mechanisms.In addition,we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment,pest management options,and the mechanisms of root-canopy interactions.This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.

Millet/peanut intercropping at a moderate N rate increases crop productivity and N use efficiency,as well as economic benefits,under rain-fed conditions

Cereal and legume intercropping has been widely adopted to increase crop productivity in sustainable farming systems worldwide.Among different intercropping combinations,millet and peanut intercropping can be adapted to most waterlimited areas.However,there are few studies on the differences in yield characteristics and nitrogen use efficiency between millet/peanut intercropping and monocultures under different nitrogen (N) application rates.The objective of this study was to determine the yield advantages and economic benefits,as well as the appropriate N application rate,of millet/peanut intercropping.A two-yearfield experiment was conducted with three cropping patterns (monoculture millet,monoculture peanut and millet/peanut intercropping) and four N rates (0,75,150 and 225 kg ha^(-1)).The results showed that the land equivalent ratio (LER) and net effect (NE) of the intercropping system reached their highest levels at the N input of 150 kg ha^(-1)in 2018 and 2019 (1.04 for LER,0.347 Mg ha^(-1)for NE,averaged across two years).Millet was the dominant crop in the intercropping system (aggressivity of millet and peanut (Amp)>0,competitive ratio of millet and peanut (CRmp)>1),and millet yields achieved their highest values at N inputs of 225 kg ha^(-1)for monoculture and 150 kg ha^(-1)for intercropping.NUE reached its highest levels with N inputs of 150 kg ha^(-1)for all planting patterns over the two years.Intercropping combined with an N input of 150 kg ha^(-1)achieved the highest net income of 2 791 USD ha^(-1),with a benefit-cost ratio of 1.56,averaged over the two years.From the perspective of economics and agricultural sustainable development,millet/peanut intercropping at 150 kg N ha^(-1)seems to be a promising alternative to millet or peanut monoculture.

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 Different Intercropping Modes on Growth, Yields and Economic Benefit of Cassava and Peanut in Symbiotic Period

[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava （M1） and sole cropping of peanut （M2） as control groups, effects of intercropping of cassava with 1 row, 2 rows and 3 rows of peanut （M3, M4 and M5）on crop growth, yields and economic benefit were studied. [Result] Intercropping affected both growth and yields of cassava and peanut. Growth competition existed between cassava and peanut, and plant heights of cassava and peanut changed similarly. In late stages of intercropping, treatments M1, M2 and M5 showed higher plant heights under no nitrogen application, while treatment M3 and M4 exhibited higher plant heights under nitrogen application; intercropping improved leaf temperature, but no obvious law could be observed among different intercropping treatments; and intercropping improved total dry matter amount, which was the highest in M5 in root expanding stage and on the 30th day of the expanding stage, and the highest in M4 on the 60th day of the expanding stage. Intercropping reduced the yield of single plant, but improved the economic benefit of red upland soil; and under no nitrogen application and nitrogen application, cassava yields decreased by 25.35% and 14.55%, respectively, peanut yields decreased by 28.76% and 52.60%, respectively, while economic benefit increased by 72.90% and 56.82%, respectively. [Conclusion] Compared with sole cropping, interplanting cassava with 1 row, 2 rows or 3 rows of peanut could all improve economic benefit, and the economic benefit increased with number of rows of interplanted peanut increasing.

Research on Efficiency Improving Technology for Intercropping Sesame (Sesamum indicum) and Peanut (Arachis hypogaea)

[Objective] The research aimed to establish a optimized combination of intercropping and fertilization application technology of intercropping sesame （Sesamum indicum） and peanut（Arachis hypogaea）. [Method] Double factor randomized block design （2 fertilization methods and 5 ratios） was adopted, with 10 treatments, 3 repeats. There were a total of 30 plots, with plot area of 12.0 m2. Two fertilization methods included C1 [base fertilizer （540 g/plot compound fertilizer ＋ topdressing （90 g urea）] and C2 [all as base fertilizer （540 g/plot compound fertilizer）]. Five different proportions （sesame： peanut） were M1（2∶4）, M2（2∶6）, M3（1∶4）, monoculture sesame （CK1） and monoculture peanut （CK2）, respectively. [Result] Output value and land equivalent ratio （LER） of C1M2 treatment （6 lines peanut/2 lines sesame, base fertilizer 540 g/plot （compound fertilizer） ＋ （topdressing urea 90 g） were the highest of 22 378.68 yuan/hm2 and 1.56 respectively; sesame yield was 641.64 kg/hm2 and peanut yield was 2 506.67 kg/hm2. Output-input ratio was 4.94. The income was increased by 32.32% and 95.97% compared with only planting of peanuts and sesame. [Conclusion] The study provided a theoretical basis for finding the best intercropping combinations of sesame and peanut and rational application fertilizations.

Analysis on Waxy Corn/Soybean Intercropping Pattern and Economic Benefit

The research mainly analyzed effects of waxy corn/soybean intercropping on yields of the two crops, as well as agronomic characters, and the economic benefits of the mode. The results showed that although yields of waxy corn and soybean went down by 21.19% and 31.04% per unit area, land equivalent ratio（1.48） kept higher than 1, suggesting the intercropping improves land use rate. Besides, due to the practice of intercropping, many characters of waxy corn grew, but of soybean declined. The economic benefits from high to low were waxy corn/soybean intercropping, monoculture of waxy corn, and monoculture of soybean.

Biochemical and microbial properties of rhizospheres under maize/ peanut intercropping

Maize/peanut intercropping system shows the significant yield advantage. Soil microbes play major roles in soil nutrient cycling and were affected by intercropping plants. This experiment was carried out to evaluate the changing of rhizosphere microbial community composition, and the relationship between microbial community and soil enzymatic activities, soil nutrients in maize/peanut intercropping system under the following three treatments： maize （Zea mays L.） and peanut （Arachis hypogaea L.） were intercropped without any separation （NS）, by half separation （HS） using a nylon net （50 μm） and complete separation （CS） by using a plastic sheet, respectively. The soil microbial communities were assessed by phospholipid fatty acid （PLFA）. We found that soil available nutrients （available nitrogen （Avail N） and available phosphorus （Avail P）） and enzymatic activities （soil urase and phosphomonoesterase） in both crops were improved in NS and HS treatments as compared to CS. Both bacterial and fungal biomasses in both crops were increased in NS followed by HS. Furthermore, Gram-positive bacteria （G＋） in maize soils were significant higher in NS and HS than CS, while the Gram-negative （G-） was significant higher in peanut soil. The ratio of normal saturated to monounsaturated PLFAs was significantly higher in rhizosphere of peanut under CS treatment than in any other treatments, which is an indicator of nutrient stress. Redundancy analysis and cluster analysis of PLFA showed rhizospheric microbial community of NS and HS of both plants tended to be consistent. The urase and Avail N were higher in NS and HS of both plants and positively correlated with bacteria, fungi （F） and total PLFAs, while negatively correlated with G＋/G- and NS/MS. The findings suggest that belowground interactions in maize/peanut intercropping system play important roles in changing the soil microbial composition and the dominant microbial species, which was closely related with the improving of soil available nutrients （N and P） and enzymatic activities.

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.

Maize/peanut intercropping increases photosynthetic characteristics, 13C-photosynthate distribution, and grain yield of summer maize

Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in Shandong, China. Treatments included sole maize (SM), sole peanut (SP), and an intercrop consisting of four rows of maize and six rows of peanut (IM and IP). The results showed that the intercropping system had yield advantages based on the land equivalent ratio (LER) values of 1.15 and 1.16 in the two years, respectively. Averaged over the two years, the yield of maize in the intercropping was increased by 61.05% compared to that in SM, while the pod yield of peanut was decreased by 31.80% compared to SP. Maize was the superior competitor when intercropped with peanut, and its productivity dominated the yield of the intercropping system in our study. The increased yield was due to a higher kernel number per ear (KNE). Intercropping increased the light transmission ratio (LTR) of the ear layer in the maize canopy, the active photosynthetic duration (APD), and the harvest index (HI) compared to SM. In addition, intercropping promoted the ratio of dry matter accumulation after silking and the distribution of 13C-photosynthates to grain compared to SM. In conclusion, maize/peanut intercropping demonstrated the potential to improve the light condition of maize, achieving enhanced photosynthetic characteristics that improved female spike differentiation, reduced barrenness, and increased KNE. Moreover, dry matter accumulation and 13C-photosynthates distribution to grain of intercropped maize were improved, and a higher grain yield was ultimately obtained.

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.

The Effects of Peanut Intercropping with Different Gramineous Species and Their Intercropping Model on Iron Nutrition of Peanut

The effects of peanut intercropped with five different gramineous species with different phyto-siderophore release rate on iron nutrition of peanut were studied in field experiment. The rate of phyto-siderophore release of five gramineous species was as following: barley>oats>wheat>>maize>sorghum. The results showed that intercropping of peanut with five gramineous species could improve iron nutrition of peanut respectively. This indicated that root exudates, especially for phytosiderophore of gramineous plants played an important role in improvement of iron nutrition of peanut. Although phytosiderophore release rates of maize and sorghum were lower than those of barley, oats and wheat, the five gramineous species had the same effects on iron improvement of peanut. The less phytosiderophore release of maize was enough to improve iron nutrition of peanut in intercropping system. For every intercropping system, intercropping model I ( the ratio of gramineous plants : peanut : gramineous plants was 2 : 3:2) was much better in improvement of iron nutrition of peanut than that of intercropping model I (the ratio of gramineous plants : peanut: gramineous plants was 2: 6:2). This led to have greater rhizosphere effect of gramineous plants on iron nutrition of peanut in intercropping model I than intercropping model I .

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.

Competitiveness and Profitability of Intercropping Sunflower with Peanut under Different Irrigation Water Levels and Potassium Fertilizer Rates

A two-year study was carried out at Ismailia Agricultural Research Station, Egypt during 2016 and 2017 summer seasons to evaluate competitive effects of intercropping sunflower and peanut under different drip irrigation water amounts and K fertilizer rates for increasing farmer profitability. Three irrigation amounts (70%, 100% and 120% ETo), three K fertilizer levels (57, 86 and 114 K2O kg/ha) and four intercropping patterns of sunflower and peanut (different spatial arrangements) were implemented. The experimental design was strip split plot with three replications. The results showed that there were no significant differences between 100% and 120% ETo on most of yield traits of the intercrops. The highest K fertilizer level had the highest values of most yield traits of the intercrops. The highest values of peanut and sunflower traits were obtained from intercropping sunflower with peanut, where peanut seeds were sown on both sides of all the raised beds, sunflower seeds were sown on one row above the raised beds and the following bed was left without intercropping (P1). Thus, to attain the highest yield of intercrops and water equivalent ratio (WER), the lowest competitive pressure and the highest farmer profitability, 120% ETo, 114 K2O kg/ha and P1 intercropping pattern should be implemented. This research found that the result of competitiveness was consistent with the result of profitability.

Effect of Application of a Bacteria Inoculant and Wheat Bran on Fermentation Quality of Peanut Vine Ensiled Alone or with Corn Stover

To find an effective method for ensiling peanut vine （PV）, fermentation characteristics and nutritional values of PV silage and the mixture of PV with corn stover （CS） silage in a ratio of 1 ： 1 fresh weight, prepared by adding lactic acid bacteria （LAB）, 10% wheat bran （WB） and LAB＋WB at ensiling were evaluated in 2009 and 2010. The fermentation qualities of PV silage ensiled with the LAB and WB additives were improved compared with those of the control （PV ensiled alone）. However, the pH did not decline to the critical level of 4.2, and the nutritional values of the silage were not protected against losses in the LAB and WB addition silages. Ensiling PV in mixture with CS generated optimal moisture content and buffering capacity （BC） of ensiled materials. After adding the LAB and WB additives to mixture silage, especially adding LAB＋WB, the fermentation qualities and nutritional values of the mixture silage were improved significantly （P〈0.05）, and the Flieg＇s score reached to 99. The result suggested that it is a feasible method to ensile the mixed materials of PV with CS by adding LAB and high concentration of water soluble-carbohydrate materials for providing a good fermentation quality of PV silage.

A Comparative Study on the Utilization of Corn Pericarp and Peanut Hull in the Production of Ethanol and the Impact on Food Economics

Corn pericarp and peanut hull (lignocellulosic materials) which are food industry by-products were used as substrates in this study. Alkaline hydrogen peroxide (H2O2) pretreatments at 0%, 2.5% and 5% were used for the removal of lignin. Simultaneous Saccharification and Fermentation (SSF) and Separate Hydrolysis and Fermentation (SHF) were conducted using Aspergillus niger (strain 201201) and Saccharomyces cerevisiae (strain 26603). Aspergillus niger was added on day 1 to all samples with inoculation treatments of S. cerevisiae at one-day intervals (A = Day 1, B = Day 2, C = Day 3 and D = Day 4). Pretreatment with 2.5% H2O2 was more beneficial in the removal of lignin for both substrates. Corn pericarp yielded an ethanol concentration of 22.2 g/L in C and 21.78 g/L in D of 2.5% H2O2 pretreatment. Peanut hull with 2.5% H2O2 pretreatment in D yielded a higher concentration at 10.38 g/L compared to other inoculation treatments. The highest ethanol yielded on a percentage basis for corn pericarp was 45.04% in C of 2.5% H2O2 pretreatment and 24.6% in D of 2.5% H2O2 pretreatment for peanut hull.

混合比例、菌剂和压实密度对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响

本试验旨在研究混合比例、菌剂和压实密度对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。试验分为2部分,试验1研究混合比例和菌剂对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。将玉米秸秆和花生秧按5个混合比例(4∶0、3∶1、2∶2、1∶3、0∶4)进行混合,每个比例下设4个组,分别为对照组(CON组,喷洒无菌生理盐水)、植物乳杆菌组(LP组,喷洒1×10^(6)CFU/g植物乳杆菌)、粪肠球菌组(EF组,喷洒1×10^(6)CFU/g粪肠球菌)、植物乳杆菌+粪肠球菌组(LP+EF组,喷洒5×10^(5)CFU/g植物乳杆菌+5×10^(5)CFU/g粪肠球菌),每组3个重复,厌氧发酵60 d。试验2研究压实密度和菌剂对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。将玉米秸秆和花生秧按3∶1比例混合后,按不同压实密度(300、450、600 kg/m^(3))进行发酵,每个压实密度下设4个组(同试验1),每组3个重复,厌氧发酵60 d。试验1结果表明:1)随着花生秧比例的提高,有机物、中性洗涤纤维和水溶性碳水化合物含量显著降低(P<0.05),粗蛋白质含量显著升高(P<0.05)。与对照组相比,EF和LP+EF组的中性洗涤纤维含量显著降低(P<0.05),EF组的氨态氮含量显著降低(P<0.05)。2)混合比例对乳酸菌和霉菌数量无显著影响(P>0.05)。与对照组相比,LP、EF和LP+EF组的乳酸菌数量显著升高(P<0.05),LP+EF组的霉菌数量显著降低(P<0.05)。3)混合比例为2∶2组的玉米赤霉烯酮含量显著高于其他各组(P<0.05),混合比例为3∶1和2∶2组的赭曲霉毒素含量显著低于混合比例为4∶0组(P<0.05)。与对照组相比,LP+EF组的玉米赤霉烯酮含量显著降低(P<0.05)。4)混合比例为2∶2组的pH显著高于其他各组(P<0.05),混合比例为3∶1组的乳酸含量显著高于混合比例为2∶2组(P<0.05),混合比例为3∶1组的乙酸含量显著低于其他各组(P<0.05),混合比例为3∶1组的丁酸含量显著低于混合比例为4∶0组(P<0.05)。与对照组相比,LP+EF组的pH显著降低(P<0.05),乳酸含量显著升高(P<0.05);EF组的乙酸含量显著降低(P<0.05)。试验2结果表明:1)压实密度为600 kg/m^(3)组的有机物、粗蛋白质含量显著低于压实密度为300 kg/m^(3)组(P<0.05),水溶性碳水化合物含量显著高于其他各组(P<0.05);随着压实密度的增加,氨态氮含量显著降低(P<0.05)。与对照组相比,EF组的有机物含量显著升高(P<0.05),LP+EF组的粗蛋白质含量显著升高(P<0.05)。2)压实密度对乳酸菌和霉菌数量无显著影响(P>0.05)。与对照组相比,LP和LP+EF组的乳酸菌数量显著升高(P<0.05),LP、EF和LP+EF组的霉菌数量显著降低(P<0.05)。3)压实密度为450和600 kg/m^(3)组的玉米赤霉烯酮和伏马毒素含量显著高于压实密度为300 kg/m^(3)组(P<0.05)。与对照组相比,LP+EF组的玉米赤霉烯酮含量显著降低(P<0.05)。4)压实密度对pH无显著影响(P>0.05)。压实密度为600 kg/m^(3)组的乳酸含量显著高于压实密度为300 kg/m^(3)组(P<0.05),压实密度为300 kg/m^(3)组的乙酸和丁酸含量显著高于其他各组(P<0.05)。综合各项指标,推荐玉米秸秆和花生秧混合青贮的适宜混合比例为3∶1,菌剂为植物乳杆菌和粪肠球菌联合添加,压实密度为450~600 kg/m^(3)。

盐碱地花生棉花等幅间作对花生光合特性及产量效益的影响

为充分利用盐碱地土地及温光热资源,明确盐碱地花生/棉花等幅间作种植模式下,不同垄行位置对花生光合产物积累和光合特性的影响,提高盐碱地农业生产综合效益,在田间条件下,采用花生/棉花6∶4等幅间作周年轮作高效种植模式,研究花生带不同垄行位置对其光合产物积累、光照强度、叶绿素荧光特性等的影响及产量和效益的变化。结果表明:(1)盐碱地花生/棉花等幅间作种植模式较花生单作可显著增加花生主茎高、侧枝长、功能叶片非光化学荧光淬灭系数(NPQ),显著降低生物量、相对叶绿素含量(SPAD)、叶面积系数(LAI)、净光合速率(P_(n))、蒸腾速率(T_(r)),产量明显降低;间作棉花果枝数、单株铃数、铃重和产量均明显提高,间作系统综合经济效益显著提高。(2)间作系统中花生带两边垄行(IP1、IP3)、单作花生和单作棉花的冠层光照强度峰值均出现在12:00,但中间垄行(IP2)花生冠层辐射强度峰值滞后到14:00,且间作花生带两边垄行冠层光照度显著低于花生单作处理。(3)间作系统中,花生花针期后垄行位置对光合效率的影响显著,中间垄行SPAD、LAI和NPQ值均显著高于两边垄行,而两边垄行间无明显差异;但P_(n)、气孔导度(G_(s))和T_(r)受试点和垄行位置影响显著,其中东营市试点花生各生育期的各垄行位置间均无显著差异,而高唐县试点间作花生功能叶P_(n)、G_(s)和T_(r)均显著低于单作处理,且间作处理的IP2垄行显著高于IP1、IP3两边垄行。(4)两试点间作棉花和花生产量低于其单作处理,但综合效益较传统植棉收益分别提高11.94%(东营)和27.08%(高唐),间作系统土地当量比大于1.02。

饲用高粱、青贮玉米带状间作苗后除草剂筛选及安全性评价

对饲用高粱、青贮玉米带状间作地用40%甲磺草胺悬乳剂、48%麦草畏水剂及25%二氯喹啉酸悬乳剂3种除草剂单剂和复配使用的杂草防除效果和安全性进行评价。结果表明,40%甲磺草胺悬乳剂、48%麦草畏水剂和25%二氯喹啉酸悬乳剂均对间作饲用高粱和青贮玉米具有良好的安全性,且以40%甲磺草胺悬乳剂540 g·hm^(-2)+48%麦草畏水剂450 m L·hm^(-2)+25%二氯喹啉酸悬乳剂630 g·hm^(-2)复配制剂除草效果表现最优,在饲用高粱3~4叶期喷施,15 d对田间总草(田间全部杂草)防除效果可达93.64%,30 d防除效果为92.80%。

等带宽间作模式下不同玉米花生行比对花生光合特性和系统产量的影响

【目的】明确相同带宽条件下不同玉米花生种植行比对花生光合特性和系统产量的影响,为构建适宜行比的玉米花生带状间作模式提供理论参考和技术支持。【方法】以玉米花生带状间作系统为对象,设置玉米单作,花生单作,玉米花生间作(3.6 m的总带宽,行比分别为2∶6、4∶4、6∶2),研究不同行比对间作花生干物质积累、叶面积指数、叶片光合参数、产量构成和玉米花生系统产量的影响。【结果】3种间作模式的干物质量和叶面积指数均小于单作,其中2∶6种植模式在花生生育后期的叶面积指数较4∶4和6∶2分别提高30.07%和44.19%,等带宽间作体系下相对较少的玉米行比可以增加间作花生的叶绿素含量和光合速率,保持花生叶片较高的光合能力,从而获得产量优势。间作显著降低了玉米的穗数、穗粒数和百粒重以及花生的单株饱果数和百果重,系统产量以2行玉米6行花生的种植模式最高,为13749.9 kg/hm^(2),3种间作模式的土地当量比均大于1,且综合产量均显著高于单作玉米和单作花生。【结论】在玉米花生等带宽间作模式下,花生行比的增加缓解了玉米的荫蔽效应,改善了花生的光合能力,同时提高土地利用率,实现稳粮增油、均衡生产。

冬小麦-夏玉米Ⅱ夏花生周年种植的农田温室气体排放及碳足迹评价

为探究冬小麦-夏玉米Ⅱ夏花生周年种植模式对农田温室气体排放及碳足迹的影响,设置冬小麦-夏玉米、冬小麦-夏花生、冬小麦-夏玉米Ⅱ夏花生3种轮作种植方式;其中夏玉米Ⅱ夏花生间作设置3∶4,3∶6和6∶8三种行比。通过大田试验研究了周年农田温室气体排放和碳足迹特征。结果表明,夏玉米Ⅱ夏花生种植模式能够减少农田温室气体的排放,与玉米单作相比,土壤CO_(2)和N_(2)O的平均排放通量降幅分别为10.24%~18.75%和10.78%~23.93%、排放总量降幅分别为8.30%~19.12%和14.09%~26.81%。间作减少了后茬冬小麦(轮作模式下)的温室气体排放,间作处理的后茬冬小麦较玉米单作处理的后茬冬小麦土壤CO_(2)排放通量减少3.79%、排放总量减少3.84%;土壤N_(2)O排放通量减少16.80%、排放总量减少17.66%;土壤CH_(4)排放总量呈现“汇”现象。此外,单作玉米生产过程中碳足迹主要来源是氮肥,占总排放的49.13%;单作花生生产过程中碳足迹主要来源是氮肥和地膜,分别占总排放的23.77%和26.06%;间作模式下碳足迹主要来源是氮肥、柴油和地膜,分别占总排放的31.50%、16.74%、17.92%。间作模式增加了后茬小麦碳排放效率、降低了全球增温潜势和温室气体排放强度。综上,冬小麦-夏玉米Ⅱ夏花生(间作玉米花生行比3:6)周年种植模式能够减少农田碳排放与作物生产过程中的碳足迹,具有良好的生态效益。