镉富集植物油菜与玉米间作对玉米吸收积累镉的影响

采用室内盆栽试验,在不同镉(Cd)添加水平下(0、2、5和10 mg·kg~(-1),分别记为Cd0、Cd2、Cd5和Cd10),研究玉米/油菜间作对营养生长期玉米生长和吸收积累Cd的影响。结果表明:间作促进了玉米生长,除Cd2处理外,间作玉米(Cd0、Cd5、Cd10)生物量比单作高19%~50%(P0.05);随着土壤中Cd浓度的增加,玉米各器官Cd含量也呈逐步增加的趋势,低、中浓度Cd污染条件下(Cd0、Cd2、Cd5),玉米/油菜间作可以阻控玉米地下部Cd向地上部转移,尤其是向叶转移,其中Cd2处理中间作玉米根系Cd含量与单作无显著差异,而间作玉米叶的Cd含量比单作低40%(P0.05);Cd5处理间作玉米根系Cd含量较单作显著增加25%(P0.05),而间作玉米叶的Cd含量较单作无显著增加;同处理间作玉米茎的Cd含量与单作间无显著差异;当土壤Cd污染浓度过高时,阻控作用会转变成促进效应,Cd10处理中间作玉米根系Cd含量与单作间无显著差异,而间作玉米叶、茎Cd含量比单作高17%、33%(P0.05);此外,土壤低、中浓度Cd污染条件下,间作对玉米单株Cd积累量的影响不明显,而高浓度Cd污染条件下(Cd10),间作显著提高玉米单株Cd积累量(61%)(P0.05)。因此,在低、中浓度Cd污染条件下,玉米/油菜间作对玉米吸收积累Cd有较明显的阻控效应,同时也是实现玉米安全、优质栽培的理想模式。     

栽植生姜对不同种植模式下紫色土微生物生物量及水解酶活性的影响

研究了岷江下游紫色丘陵区玉米+红薯间作、大豆单作、生姜连作、水稻-紫云英轮作等4个典型种植模式下栽植生姜后土壤微生物生物量碳、氮、磷含量和水解酶活性的变化特征.结果表明： 栽植生姜显著降低了4个种植模式下土壤微生物生物量碳、氮和磷含量,但各种植模式之间存在较大差异.其中,玉米+红薯间作和水稻-紫云英轮作模式下土壤微生物生物量碳、氮的下降幅度明显低于大豆单作与生姜连作模式,但土壤微生物生物量磷下降幅度明显较高.栽植生姜显著降低了土壤酸性磷酸酶活性,其下降幅度以玉米+红薯间作模式最大,水稻-紫云英轮作模式最小;土壤转化酶活性在生姜连作模式下显著降低;土壤脲酶活性在大豆单作、生姜连作和水稻-紫云英轮作模式下均显著降低.相对于其他模式,栽植生姜使玉米+红薯间作模式下的土壤维持了较高的转化酶和脲酶活性.     

栽植生姜对不同种植模式下紫色土微生物生物量及水解酶活性的影响

研究了岷江下游紫色丘陵区玉米+红薯间作、大豆单作、生姜连作、水稻-紫云英轮作等4个典型种植模式下栽植生姜后土壤微生物生物量碳、氮、磷含量和水解酶活性的变化特征.结果表明:栽植生姜显著降低了4个种植模式下土壤微生物生物量碳、氮和磷含量,但各种植模式之间存在较大差异.其中,玉米+红薯间作和水稻-紫云英轮作模式下土壤微生物生物量碳、氮的下降幅度明显低于大豆单作与生姜连作模式,但土壤微生物生物量磷下降幅度明显较高.栽植生姜显著降低了土壤酸性磷酸酶活性,其下降幅度以玉米+红薯间作模式最大,水稻-紫云英轮作模式最小;土壤转化酶活性在生姜连作模式下显著降低;土壤脲酶活性在大豆单作、生姜连作和水稻-紫云英轮作模式下均显著降低.相对于其他模式,栽植生姜使玉米+红薯间作模式下的土壤维持了较高的转化酶和脲酶活性.     

施氮水平和收获时期对夏玉米产量和籽粒品质的影响

为明确黄淮海夏玉米适宜的施肥量和最佳收获时期,设计了5个氮肥水平(不施肥、113、181、249和375 kg N.hm-2)和2个收获时期(S1:9月23日,农民习惯收获时间;S2:9月29日,推迟6 d收获),研究施氮量和收获时期对夏玉米产量和品质的影响.结果表明:随施肥量增加,夏玉米穗粒数、千粒重和产量均增加,但差异不显著,其中施肥量在113～181 kg N.hm-2的玉米产量、氮素利用效率均相对较高;随施肥量增加,夏玉米蛋白质和赖氨酸含量增加,淀粉含量降低.与9月23日蜡熟期收获相比,9月29日完熟期收获的夏玉米籽粒千粒重、产量、淀粉和赖氨酸含量均增加,籽粒蛋白质和脂肪含量降低.依据产量水平,黄淮海高产夏玉米区适宜的施肥量在113～180 kg N.hm-2,最佳收获时期应推迟至9月29日—10月5日.     

施氮和隔根对玉米植株生长、产量和根际微生物的影响

采用根系分隔试验,研究不同施氮水平(0.1、0.3、0.5和0.7 g· kg-1)下,玉米-大豆间作系统中根系互作对玉米植株生长、产量和根际微生物的影响.结果表明:根系互作和增施氮肥可以增加玉米株高、叶片长和叶片宽,提高玉米叶绿素含量.未隔根处理玉米成熟期的根干质量与隔根处理相比差异不显著.在0.1、0.3、0.5和0.7 g· kg-1施氮水平下,未隔根处理的单株生物量分别增加8.8％、6.3％、3.6％和0.7％,单株经济产量分别增加17.7％、10.0％、8.2％和0.9％.未隔根处理真菌和固氮菌数量与隔根相比显著增高;随着施氮水平的提高,根际细菌、真菌和放线菌的数量均呈逐渐增加趋势,而固氮菌的数量呈先增加后下降的趋势.玉米成熟期的根冠比与细菌、真菌和放线菌数量呈显著负相关,与固氮菌数量相关性不显著.根系互作有利于改善玉米植株生长,增加玉米产量和根际微生物数量,但其效果会随供氨水平的提高而减弱.     

玉米-大豆间作和施氮对玉米产量及农艺性状的影响

为研究玉米-大豆间作模式和施氮水平对玉米产量、主要农艺性状及生长动态的影响,进行2个种植模式(玉米单作和玉米-大豆间作)和2个施氮水平(0 kg/hm2,150 kg/hm2)的双因素随机区组试验,以期揭示施氮和间作对玉米产量的影响规律,为提高玉米-大豆间作系统产量提供一定的理论依据。研究结果表明:(1)与不施氮相比,施氮显著增加了春秋两季间作玉米产量,分别达到23.81%和40.99%。施氮处理下的间作玉米地上部生物量较不施氮提高了29.91%,单作模式下显著提高了40.34%,两者差异均达到显著水平。(2)与不施氮相比,施氮150 kg/hm2条件下春玉米单作和间作模式百粒重分别提高了18.92%和19.23%,秋玉米单作和间作模式百粒重分别提高了31.03%和32.75%,差异均达到显著水平。与不施氮相比,施氮150 kg/hm2条件下,单作和间作模式均显著提高秋玉米穗长。与不施氮相比,施氮150 kg/hm2条件下,单作秋玉米的穗粗提高了18.67%,差异显著。(3)施氮和间作均能促进玉米干物质累积、提高株高和叶绿素(SPAD值),且表现为施氮效果高于间作效果。总体来看,种植模式和施氮水平对玉米产量、主要农艺性状和生长动态均有一定影响,且施氮效果优于间作效果。由于土壤具有一定的供氮能力,而间作豆科能为玉米供给一定量的氮素,故对于春玉米而言,施氮效果仅在百粒重中表现,随着土壤原有氮素被玉米吸收利用减少后,供氮能力下降,在秋玉米中施氮效果显著提高。     

玉米与籽粒苋不同种植模式下植物生长及Cd累积特征

为实现Cd污染农田边生产边修复的目标,采用田间原位修复的方式,将玉米与籽粒苋在Cd污染农田中以5种不同的间作模式种植: 交替宽窄行玉米宽行间作单行籽粒苋(T₁)、交替宽窄行玉米宽行间作双行籽粒苋(T₂)、等行距双行玉米间作单行籽粒苋(T₃)、等行距双行玉米间作双行籽粒苋(T₄)、玉米/籽粒苋等4行距间作(T₅),并以玉米(CK₁)和籽粒苋(CK₂)单作种植作为对照,探究不同间作结构配置对作物与超富集植物生长及Cd累积特征的影响.结果表明: 1)与CK₁相比,各间作模式单株玉米的籽粒产量呈增加趋势;T₁间作模式玉米的籽粒产量较CK₁增加10.5%,T₄和T₅间作模式玉米的籽粒产量较CK₁分别减少6.3%和5.4%,T₂和T₃间作模式基本稳产;间作籽粒苋地上部单株生物量及单位面积产量较CK₂分别显著减少69.5%～95.7%和83.9%～96.9%. 2)各间作模式玉米籽粒Cd含量较CK₁呈减少趋势,而间作籽粒苋Cd含量较CK₂呈增加趋势. 3)与CK₂相比,各间作模式籽粒苋的富集系数、转运系数、有效转运系数均呈增加趋势;间作籽粒苋地上部Cd的单株及单位面积提取量较CK₂分别显著减少40.4%～86.7%和70.4%～88.9%;各间作模式玉米与籽粒苋地上部Cd的单位面积提取总量高于单作玉米,但低于单作籽粒苋. 4)各间作模式玉米根际土有效态Cd含量及籽粒苋根际土总Cd、有效态Cd含量分别较单作玉米及单作籽粒苋呈增加趋势,但对非根际土没有显著影响.本研究中,T₁间作模式有利于玉米籽粒产量的提高,T₅间作模式有利于籽粒苋Cd提取量的最大化.     

玉米/花生间作对土壤微生物和土壤养分状况的影响

通过大田试验,研究了玉米/花生间作对玉米和花生根区土壤微生物和土壤养分状况的影响.结果表明：与单作相比,间作能显著提高玉米和花生根区的土壤细菌数量;间作花生根区土壤真菌和放线菌数量与单作无显著差异;间作玉米根区土壤真菌和放线菌数量比单作明显提高;间作作物根区微生物群落功能多样性和代谢活性比单作有所改善.玉米/花生间作不同程度提高了整个间作系统根区的土壤碱解氮、速效磷、有机质含量及EC值,其中,间作玉米根区土壤养分的增加更为明显,说明玉米/花生间作可以较明显地改善两种作物根区的微生物和养分状况,土壤微生态环境的改善又会促进作物地上部的生长.     

减量施氮对玉米-大豆套作体系中作物产量及养分吸收利用的影响

通过田间试验研究了种植方式(玉米单作、大豆单作、玉米-大豆套作)和施氮水平(0、180、240 N kg·hm-2)对玉米和大豆产量、养分吸收及氮肥利用的影响.结果表明:与单作相比,玉米-大豆套作体系中玉米籽粒产量、地上部植株N、P、K吸收量及收获指数略有降低,而大豆籽粒产量、地上部植株N、P、K吸收量及收获指数显著提高.玉米-大豆套作系统的套作优势随施氮量的增加而降低,与当地农民常规施氮量(240 kg·hm-2)相比,减量施氮(180kg·hm-2)处理下玉米和大豆产量、经济系数,以及N、P、K吸收量和收获指数、氮肥农学利用率、氮肥吸收利用率显著提高,土壤氮贡献率降低;与不施氮相比,减量施氮降低了玉米带土壤的全N、全P含量,提高了大豆带土壤的全N、全P、全K含量和玉米带土壤的全K含量.减量施氮水平下,玉米-大豆套作系统的周年籽粒总产量、地上部植株N、P、K总吸收量均高于玉米和大豆单作,土地当量比(LER)达2.28;玉米-大豆套作系统的氮肥吸收利用率比玉米单作高20.2%,比大豆单作低30.5%,土壤氮贡献率比玉米和大豆单作分别低20.0%和8.8%.玉米-大豆套作减量一体化施肥有利于提高系统周年作物产量和氮肥利用率.     

木薯/花生间作对根际土壤微生态的影响

为了探明木薯/花生间作在增产增收的同时对土壤微生态的影响,研究木薯和花生以不同行距(30 cm,40 cm,50 cm)间作的根际土壤养分、微生物及相关酶活性的变化。结果表明:木薯/花生间作可增加根际土壤细菌、真菌、放线菌及总微生物数量和微生物多样性,30 cm间作行距的木薯、花生根际土壤微生物总数量分别比单作木薯、花生增加了129.6%和101.1%;间作根际土壤碱解氮、有效磷、有效钾和有机质含量相比单作增加,50 cm间作花生的根际土壤碱解氮、有效磷、有效钾量比单作花生增加了145.9%~195.9%,30 cm间作木薯的根际土壤有效钾、有效磷含量分别比单作木薯增加了161.8%和187.9%;木薯/花生间作的根际土壤过氧化氢酶、酸性磷酸酶活性活性相比单作升高,间作土壤脲酶和蛋白酶活性相比单作降低,30 cm间作木薯的根际土壤过氧化氢酶活性比单作木薯增加了59.2%,50 cm间作花生的根际土壤蔗糖酶活性比单作花生增加了97.4%。可见,木薯/花生间作可改善根际土壤微生态坏境,且适宜的间作行距更利于土壤养分含量和微生物数量的增加。     

减量施氮对玉米-大豆套作系统下作物氮素吸收和利用效率的影响

为探索玉米-大豆套作系统中作物对N素吸收的差异特性,揭示减量施N对玉米-大豆套作系统的N高效利用机理。利用15N同位素示踪技术,结合小区套微区多年定位试验,研究了玉米单作(MM)、大豆单作(SS)、玉米-大豆套作(IMS)及不施N(NN)、减量施N(RN:180 kg N/hm2)、常量施N(CN:240 kg N/hm2)下玉米、大豆的生物量、吸N量、N肥利用率及土壤N素含量变化。结果表明,与MM(SS)相比,IMS下玉米茎叶及籽粒的生物量、吸N量降低,15N%丰度及15N吸收量增加,大豆籽粒及植株的生物量、吸N量及15N吸收量显著提高;IMS下玉米、大豆植株的N肥利用率、土壤N贡献率、土壤15N%丰度降低,15N回收率显著增加。施N与不施N相比,显著提高了单、套作下玉米、大豆植株的生物量、吸N量、15N丰度及15N吸收量;RN与CN相比,IMS下,RN的玉米、大豆植株总吸N量提高13.4%和12.4%,N肥利用率提高213.0%和117.5%,土壤总N含量提高12.2%和11.6%,土壤N贡献率降低12.0%和11.2%,玉米植株15N吸收量与15N回收率提高14.4%和52.5%,大豆的则降低57.1%和42.8%,单作与套作的变化规律一致。玉米-大豆套作系统中作物对N素吸收存在数量及形态差异,减量施N有利于玉米-大豆套作系统对N肥的高效吸收与利用,实现作物持续增产与土壤培肥。     

Nitrogen Fixation of Faba Bean (Vicia faba L.) Interacting with a Non-legume in Two Contrasting Intercropping Systems

A field experiment was carried out to quantify biological nitrogen fixation (BNF) using the ¹⁵N isotope natural abundance method in maize (Zea mays L.)/faba bean (Vicia faba L.) and wheat (Triticum aestivum L.)/faba bean intercropping systems. Faba bean was yielding more in the maize/faba bean intercropping, but not in the wheat/faba bean intercropping. Biomass, grain yield and N acquisition of faba bean were significantly increased when intercropped with maize, and decreased significantly with wheat, irrespective of N-fertilizer application, indicating that the legume could gain or lose productivity in an intercropping situation. There was yield advantage of maize/faba bean intercropping, but no in wheat/faba bean intercropping. The grain yield of the faba bean intercropped with maize was greater than that of faba bean monoculture due to increases of the stems per plant and the pods per stem of faba bean. N fertilization inhibited N fixation of faba bean in maize/faba bean and wheat/faba bean intercropping and faba bean monoculture. The responses of different cropping systems to N-fertilizer application, however, were not identical, with competitive intercropping (wheat/faba bean) being more sensitive than facilitative intercropping (maize/faba bean). Intercropping increased the percentage of N derived from air (%Ndfa) of the wheat/faba bean system, but not that of the maize/faba bean system when no N fertilizer was applied. When receiving 120 kg N/ha, however, intercropping did not significantly increase %Ndfa either in the wheat/faba bean system or in the maize/faba bean system in comparison with faba bean in monoculture. The amount of shoot N derived from air (Ndfa), however, increased significantly when intercropped with maize, irrespective of N-fertilizer application. Ndfa decreased when intercropped with wheat, albeit not significantly at 120 kg N/ha. Ndfa was correlated more closely with dry matter yield, grain yield and competitive ratio, than with %Ndfa. This indicates that that total dry matter yield (sink strength), not %Ndfa, was more critical for the legume to increase Ndfa. The results suggested that N fixation could be improved by yield maximization in an intercropping system.     

Root and hyphal interactions influence N transfer by arbuscular mycorrhizal fungi in soybean/maize intercropping systems

In maize-soybean intercropping systems, the transfer of N from soybean to maize gives the intercropping system the advantage of improved N utilization and higher yields. Mycorrhiza acts as an important pathway for N transfer, providing a constant supply of N to sustain the growth and development of maize in its early stages. However, it is not clear how arbuscular mycorrhizal fungi (AMF) drive the transfer of N from soybean to maize in the intercropping system. Therefore, we quantified the amount of N transferred from soybean to maize under low and high N levels in the intercropping system, and the abundance and diversity of AMF involved in N transfer (¹⁵N-AMF) under different conditions by ¹⁵N leaf marker and DNA-SIP technology. We found that the interaction between roots and reducing the application of N fertilizer increased the amount of N transfer from soybean to maize. Compared with plastic plate separation (PS), no separation (NS) and mesh separation (MS) significantly increased the N fixation rate (from 14.33% to 39.09%), and the amount of N transfer under NS was 1.95–3.48 times that under MS. N transfer from soybean to maize ranged from 9.7 to 43.42 mg per pot in the no N treatment, while the addition of N fertilizer reduced N transfer by 14.12–66.28%. This is due to root interaction and reduced N fertilization increased the abundance and diversity of the ¹⁵N-AMF community, thereby promoting AMF colonization of maize and soybean roots. AMF colonization in soybean and maize roots under NS treatment was 6.47–17.24% higher than under MS treatment in all three levels of N addition. The increase of mycorrhiza in root system increased the N transfer from soybean to maize significantly. These results suggest that reduced N fertilizer in maize-soybean intercropping systems can increase N transfer by the mycorrhizal pathway, meeting maize N requirements and reducing chemical N fertilizer, which is important for sustainable agricultural development.     

Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat

Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha^-1), and economic benefit (3,408 USD ha^-1). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating four maize rows with six soybean rows was the optimum row ratio in maize || soybean system, though this needs to be further confirmed by pluri-annual trials.     

Effects of intercropping sugarcane and soybean on growth, rhizosphere soil microbes, nitrogen and phosphorus availability

The effects of sugarcane plantation intercropped with soybean on plant growth, yield, enzyme activity, nitrogen and phosphorus contents, the microbe quantity of rhizosphere soil were investigated. Results showed that dry weight of biomass and yield under sugarcane/soybean intercropping were increased by 35.44 and 30.57 % for sugarcane, and decreased by 16.12 and 9.53 % (100-grain weight) for soybean, respectively. The nitrogenase activity of intercropping soybean nodule was significantly increased by 57.4 % as compared with that in monoculture models. The urease activities of intercrops sugarcane and soybean were promoted by 89 and 81 % as compared to that of the monoculture models, respectively. The effective nitrogen and phosphorus contents of rhizospheric soil of intercrops sugarcane and soybean were increased by 66 and 311.7 %, respectively, as compared to those in the monoculture system. Microbe number of rhizosphere soil in the intercropping pattern increased significantly as compared to those in the monoculture models. The quantities of bacteria, fungi, and actinomyces increased by 42.62, 14.5 and 78.5 % in the intercropping sugarcane, while the intercropping soybean increased by 188, 183 and 73 %, respectively. Therefore, growing sugarcanes in combination with soybean can be considered a good agriculture management practice, helping to promote plant growth, yield and increase soil nutrients.     

间作对植株生长及养分吸收和根际环境的影响

通过盆栽实验研究了线辣椒和玉米间作对其植株生长、矿质养分吸收、根际环境以及铁载体分泌的影响,以探索间作促进铁、磷等养分吸收利用的可能生理机制.结果表明:(1)与单作相比,间作线辣椒地上部干重降低23.0%,根系干重增加44.2%,玉米地上部和根系的干重分别增加8.7%和22.9%;间作线辣椒根冠比和根系活力分别显著提高86.4%和29.8%;间作线辣椒、玉米叶绿素含量分别显著提高12.6%和7.8%.(2)与单作相比,间作线辣椒的铁、锌、锰含量分别增加1.50倍、1.39倍和1.34%,而间作玉米则无显著变化;间作线辣椒和玉米的钙含量都显著低于相应单作,氮含量没有显著变化,但磷、钾含量显著增加.(3)间作线辣椒和玉米的根际土、非根际土的酸性磷酸酶活性及根系酸性磷酸酶活性都显著高于相应单作,而其根际土和非根际土的pH值无显著变化;间作玉米根系的铁载体分泌比单作减少32.8%,间作线辣椒根系的铁还原酶活性是单作的1.10倍.研究发现,线辣椒/玉米间作能通过影响根际生物学特征和化学过程提高植株的铁、锌、磷和钾养分水平,缓解养分胁迫,是一种很有推广价值的种植模式.     

玉米-花生间作对作物产量和光合作用光响应的影响

研究了玉米-花生间作对玉米、花生经济产量及功能叶片光合作用光响应的影响.结果表明：间作体系总体表现出明显的产量优势，2004和2005年分别为2 896和2 894 kg·hm^-2，土地利用率提高了14%～17%；玉米-花生间作提高了玉米功能叶片的光饱和点、光补偿点和强光时的光合速率，降低了花生功能叶片的光补偿点和光饱和点，但提高了花生表观量子效率和弱光时的光合速率.表明间作提高了玉米对强光和花生对弱光的利用能力，从而使间作体系表现出明显的产量优势.     

Intercropping Enhances Productivity and Maintains the Most Soil Fertility Properties Relative to Sole Cropping

Yield and nutrient acquisition advantages are frequently found in intercropping systems. However, there are few published reports on soil fertility in intercropping relative to monocultures. A field experiment was therefore established in 2009 in Gansu province, northwest China. The treatments comprised maize/faba bean, maize/soybean, maize/chickpea and maize/turnip intercropping, and their correspoding monocropping. In 2011 (the 3^rd year) and 2012 (the 4^th year) the yields and some soil chemical properties and enzyme activities were examined after all crop species were harvested or at later growth stages. Both grain yields and nutrient acquisition were significantly greater in all four intercropping systems than corresponding monocropping over two years. Generally, soil organic matter (OM) did not differ significantly from monocropping but did increase in maize/chickpea in 2012 and maize/turnip in both years. Soil total N (TN) did not differ between intercropping and monocropping in either year with the sole exception of maize/faba bean intercropping receiving 80 kg P ha⁻¹ in 2011. Intercropping significantly reduced soil Olsen-P only in 2012, soil exchangeable K in both years, soil cation exchangeable capacity (CEC) in 2012, and soil pH in 2012. In the majority of cases soil enzyme activities did not differ across all the cropping systems at different P application rates compared to monocrops, with the exception of soil acid phosphatase activity which was higher in maize/legume intercropping than in the corresponding monocrops at 40 kg ha⁻¹ P in 2011. P fertilization can alleviate the decline in soil Olsen-P and in soil CEC to some extent. In summary, intercropping enhanced productivity and maintained the majority of soil fertility properties for at least three to four years, especially at suitable P application rates. The results indicate that maize-based intercropping may be an efficient cropping system for sustainable agriculture with carefully managed fertilizer inputs.