Growth Behavior,Nutrient Harvest Index,and Soil Fertility in Okra-Pea Cropping System as Influenced by AM Fungi,Applied Phosphorus,and Irrigation Regimes in Himalayan Acidic Alfisol

The impact of arbuscular mycorrhizal fungi (AMF), inorganic phosphorus (P), and irrigation regimes was studied in an okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system in an acidic Alfisol. Experimentation was carried out at Palampur, India, in a randomized bock design (RBD), replicated three times with fourteen treatments comprising AM fungi (Glomus mosseae), inorganic phosphorus (50, 75, and 100% soil-test-based recommended P dose), irrigation regimes (at 40 and 80% available water capacity), generalized recommended NPK and irrigations (GRD), and farmers’ practice. Effects of AM fungi on plant height, leaf area index (LAI), and dry-matter accumulation (DMA) were nominal at early crop growth stage, i.e., 50 DAS (days after sowing). However, at 100 DAS, AMF imbedded treatments led to higher plant height (4%), LAI (3%), and DMA (6%) in okra, whereas in pea the magnitude of increase in these parameters following AMF inoculation was 6, 5, and 8%, respectively, over non-AMF counterparts. AMF + 75% soil-test-based P dose at either of these irrigation regimes gave statistically similar yields in both okra and pea as that obtained under 100% soil-test-based P dose at either of two irrigation regimes, thus indicating an economy of about 25% in soil-test-based P dose. Regarding nutrient harvest index in okra and pea, statistically similar values were registered with most nutrients under both AMF inoculated and non-AMF counterparts. In the case of okra, P harvest index was registered less by 3% with AMF inoculation; however, its magnitude increased by 3% in pea following AMF inoculation compared to non-AMF counterparts at similar levels of P and irrigation. At completion of two cycles of okra-pea system, AMF imbedded treatments did not alter available soil nutrient status significantly in comparison to non-AMF counterparts. Overall, current study suggests that practice of AMF inoculation has great potential in enhancing growth parameters for better productivity, fertilizer-P economy, and nutrient harvest efficiency in okra-pea production system in Himalayan acidic Alfisol.     

AM fungi lead to fertilizer phosphorus economy and enhanced system productivity and profitability in okra (Abelmoschus esculentus L.)–pea (Pisum sativum L.) cropping system in Himalayan acid Alfisol

The present investigation was carried out at CSK Himachal Pradesh Agricultural University, Palampur, Himachal Pradesh, India, during 2009–2011 to economize inorganic phosphorus (P) and enhance profitability of okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system through arbuscular mycorrhizal fungi (AMF). A field experiment was replicated thrice in a randomized block design comprising 14 treatments involving AMF (Glomus mosseae) at varying inorganic P (50%, 75%, and 100% of recommended soil test-based P dose) and irrigation regimes (40% and 80% available water capacity] in a Himalayan acid Alfisol. In okra, AMF inoculation at varying P and irrigation regimes registered higher P response ratio (PRR), net returns (10–18%), and benefit:cost (B:C) ratio (17–49%) compared to “generalized recommended P dose (GRD)” and their non-AMF counterparts. Similarly in pea, AMF inoculation at varying P and irrigation regimes again registered higher PRR, net returns (14–23%), and B:C ratio (10–58%) compared to GRD and non-AMF counterparts. Higher system productivity (7–16%) and profitability in terms of net returns (9–23%) and B:C ratio (10–54%) were also registered in AMF-imbedded treatments compared to non-AMF counterparts. Further, “AMF + 75% soil test-based P dose” at either of these irrigation regimes registered statistically similar okra–pea system productivity and profitability as that obtained under “100% soil test-based P dose” at either of two irrigation regimes, thus indicating an economy of soil test-based applied P dose by about 25%. Overall, the current study suggests that practice of AMF inoculation has great potential in enhancing system productivity and profitability besides cutting down about 25% inorganic P requirement in okra–pea production system in the Himalayan acid Alfisol.     

Effect of AM fungi and phosphorus fertilization on P-use efficiency,nutrient acquisition and root morphology in pea (Pisum sativum L.) in an acid Alfisol

Phosphorus (P) availability to plants is a major constraint in acid soils. A study was conducted to determine the effect of arbuscular mycorrhizal fungi (AMF) under varying inorganic P and irrigation regimes on P availability and P-use efficiency in garden pea (Pisum sativum L.) in a Himalayan acid Alfisol. The experiment comprised of 14 treatments replicated thrice in a randomized block design. The results revealed that integrated use of AM fungi and inorganic P at either of the two irrigation regimes (IW/CPE_0.6 or IW/CPE_1.0) enhanced the green pea pod weight, green pod productivity and agronomic efficiency of applied P to the extent of 8.4%, 7.2% and 30.7%, respectively, over non-AMF counterparts as well as “generalized recommended NPK dose and irrigations (GRD).” AMF inoculation also led to enhanced nitrogen (N), P and potassium (K) acquisition (uptake) by 16.3%, 18.2% and 6% over non-AMF counterpart treatments. Further, AMF inoculation at varying P and irrigation regimes sharply enhanced the rooting depth (21.4%), root volume (23.5%), root dry weight (14.9%), root weight density (13.7%) as well as N concentration in root nodules (3.4%) over non-AMF counterparts and GRD practice. AMF also enhanced the mycorrhizal root colonization by 3.2 folds at flowering stage in AMF inoculated pea plants. AMF-imbedded treatments did not alter the available soil nutrient status (macronutrients and micronutrients) significantly in comparison to non-AMF counterparts in pea, available P status, however, increased to the extent of 6.5% over initial status. Further, AMF imbedded plots showed a slight build-up in soil organic carbon with nominal decrease in soil bulk density. AMF inoculation in pea also led to fertilizer P economy by about 25% soil-test-based P dose. Overall, AMF holds great potential in enhancing nutrient acquisition especially P besides influencing root morphology in order to harness better crop yields vis-à-vis fertilizer P economy by about 25% soil-test-based P dose in Himalayan acid Alfisol.     

Influence of Dual Inoculation of AM Fungi and Rhizobium on Growth Indices,Production Economics,and Nutrient Use Efficiencies in Garden Pea (Pisum sativum L.)

Field experimentation was conducted at Palampur, India during 2011–2012 in an acid Alfisol to quantify the influence of integrated use of arbuscular mycorrhizal fungi (AMF), Rhizobium and inorganic nitrogen (N) and phosphorus (P) on growth, productivity, profitability, and nutrient use efficiencies in garden pea (Pisum sativum L.). The experiment was laid out in randomized block design (RBD) replicated thrice comprising 13 treatments involving AMF (Glomus mosseae), Rhizobium (R. leguminosarum), and inorganic N and P fertilizers. The results revealed that dual inoculation of pea seed with AMF and Rhizobium enhanced the plant height, leaf area index, and dry matter accumulation significantly by 19.4 and 13.1, 10.7 and 10.7, and 16.6 and 16.7%, respectively at 60 and 120 days after sowing (DAS). Similarly, dual inoculation exhibited significant respective increases of 9.5 and 14.6% in absolute and crop growth rates over generalized recommended NP potassium (K) dose (GRD) during 60–120 DAS. The dual inoculation led to significant respective increases of 1.0 and 2.2, 1.06 and 1.74, 0.21 and 1.5, and 1.05 and 1.60 folds in partial factor productivity, crop recovery efficiency, physiological efficiency, and % recovery of applied N and P, respectively over GRD. The magnitude of increase in pea productivity, net returns, and boron to carbon (B:C) ratio following dual inoculation was to the tune of 20, 54.4, and 104.1%, respectively over GRD. Dual inoculation also exhibited significant increases of 19.4 and 53.1% in production and monetary efficiencies of pea over GRD. Overall, dual inoculation of AMF and Rhizobium with 75% soil-test-based N and P dose in pea has great potential in enhancing pea productivity, profitability, and nutrient use efficiency besides saving about 25% fertilizer N and P without impairing pea productivity in Himalayan acid Alfisol.     

Influence of Glomus–Rhizobium Symbiosis on Productivity,Root Morphology and Soil Fertility in Garden Pea in Himalayan Acid Alfisol

The influence of dual inoculation of arbuscular mycorrhizal fungi (AMF) and Rhizobium was assessed on garden pea productivity, root morphology and soil fertility during 2011–2012 at Palampur, India, in a medium phosphorus (P) acid Alfisol. Field experimentation comprised 13 treatments involving Rhizobium, AMF and inorganic fertilizers in (RBD) replicated thrice. The dual inoculation of Rhizobium and AMF exhibited nominal effect on pea pod length, pod girth and number of seeds per pod. However, average pod weight (APW) and productivity increased by 14.1 and 20% following dual inoculation, respectively, over generalized recommended nitrogen, phosphorus and potassium (NPK) dose general recommended dose (GRD). Dual inoculation of pea seed with both symbionts sharply increased the root volume (RV), root dry weight (RDW), root weight density (RWD) and root nodules per plant by 34.5, 13.3, 13 and 44%, respectively. Similarly, the highest AMF root colonization was registered under dual-inoculated plots compared to sole application of Rhizobium or AMF. Different treatments including dual-inoculated ones did not alter the soil organic carbon (SOC), available N, K and diethylenetriaminepentaacetic acid (DTPA)-extractable micronutrients iron, zinc, copper and manganese (Fe, Zn, Cu and Mn) status significantly; however, a nominal buildup in the above-mentioned parameters was registered under dual inoculation. Available P status increased to the tune of 6.7 and 8.7% following dual inoculation with Rhizobium and AMF over their respective sole inoculations. Overall, the current study suggests that Glomus–Rhizobium symbiosis has great potential in enhancing productivity through better proliferation of the root system and improved soil fertility status. Furthermore, dual inoculation of AMF and Rhizobium can save up to 25% fertilizer N and P in garden pea in acid Alfisol of the northwestern Himalayas (NWH).     

Agronomic bio-fortification and quality enhancement in okra–pea cropping system through arbuscular mycorrhizal fungi at varying phosphorus and irrigation regimes in Himalayan acid alfisol

A field experimentation was conducted during 2009-2011 at CSK Himachal Pradesh Agricultural University, Palampur, India characterized with wet-temperate climate and acid Alfisol soil having medium available phosphorus content. The study aimed at bio-fortification and quality enhancement of okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system through arbuscular mycorrhizal fungi (AMF) (Glomus mosseae) at varying inorganic phosphorus (50, 75, and 100% soil-test-based recommended P dose) and irrigation regimes (40 and 80% available water capacity) in a Himalayan acid Alfisol. The results revealed that AMF and inorganic P significantly enhanced the concentrations and uptake of various primary [nitrogen (N), phosphorus (P), and potassium (K)]; secondary [calcium (Ca)]; and micronutrients [iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), boron (B), and molybdenum (Mo)] in okra and pea crops. However, effects of varying irrigation regimes were found to be nominal. In okra, AMF inoculation considerably enhanced N, P, K, B, and Mo uptake by 5, 19, 3, 4, and 15%, respectively, over their non-AMF counterparts. Likewise in pea, a higher amount of N (10%), P (26%), K (7%), Fe (7%), Cu (38%), Zn (20%), Mn (4%), B (7%), and Mo (13%) uptake was registered through AMF inoculation over their non-AMF counterparts. Application of soil-test-based P dose from 50% to 100% P also resulted in significant and consistent improvement in N, P, K, B, and Mo uptake both in okra and pea and in Zn, Cu, Mn, and Fe uptake in pea crop. Magnitude of increase in Ca content was to the tune of 13 and 4%, respectively, in okra fruits and pea pods following AMF inoculation, whereas crude protein content enhanced by 4% each in both the crops. Overall, the current study demonstrates the important role of AMF in nutrient enrichment and quality enhancement of okra and pea crops in acid Alfisol, besides considerable reduction in investment on chemical fertilizers. Results of current study suggest that AMF use in Himalayan production systems is of tremendous significance to harvest nutritionally-rich farm produce for Himalayan communities suffering from malnutrition especially anemia and Zn deficiency, and equally to resource-poor Himalayan farmers who ill-afford expensive external inputs.     

Influence of Inorganic Phosphorus,VAM Fungi,and Irrigation Regimes on Crop Productivity and Phosphorus Transformations in Okra (Abelmoschus esculentus L.)–Pea (Pisum sativum L.) Cropping System in an Acid Alfisol

The present investigation was carried out at CSK Himachal Pradesh Agricultural University, Palampur, India, during 2009–2011 to economize inorganic phosphorus (P) and water needs of an okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system through vesicular arbuscular mycorrhizal (VAM) fungi (Glomus mosseae) in a Himalayan acid Alfisol. The field experiment was replicated three times in a randomized block design comprising 14 treatments consisting of 12 treatment combinations of two VAM levels [0 and 12 kg ha^?1], three phosphorus levels [50, 75, and 100% of recommended soil-test-based nitrogen (N)–P–potassium (K)], and two irrigation regimes [40 and 80% of available water-holding capacity of field soil (AWC)], in addition to one treatment with “generalized recommended NPK dose with generalized recommended irrigations (GRD)” and one treatment based on “farmers’ practice of plant nutrition and irrigation management in the region.” This article presents crop productivity and P dynamics studies during the second crop cycle of okra–pea sequence (2010–2011) and statuses of different P fractions in the soil after the second pea crop harvest during 2010–2011. Crop productivity and P uptake data in okra–pea sequence indicated that application of VAM + 75% P dose at either of two irrigation regimes did not differ significantly than GRD treatment and VAM + 100% P dose. It suggests an economy of about 25% inorganic P dose through VAM fungi. The treatments imbedded with VAM inoculation enhanced the P uptake in okra–pea system, on an average by 21% over the GRD and non-VAM-inoculated counterparts. Further, integrated application of P, VAM, and irrigation regimes evaluated in okra–pea sequence for 2 years led to greater status of water-soluble P (21%), sodium bicarbonate (NaHCO₃)–inorganic phosphorus (Pi) (11%), sodium hydroxide (NaOH)–Pi (9%), hydrochloric acid (HCl)–extractable–P (20%) over non-VAM-inoculated counterparts and low status of organic P (NaHCO₃-P_o and NaOH-P_o), all of which appreciably contributed to available P supply to plants in the present study in an acid Alfisol. The correlation coefficient reveals that contribution of inorganic P forms is highly correlated to crop productivity and total P uptake in okra and pea crops besides soil available P in the present study. Overall, it is concluded that VAM inoculation in okra–pea cropping system significantly enhanced the P availability to plants by way of enriching the labile-P pool such as water-soluble P and P loosely bound to aluminium (Al-P) and iron (Fe-P) on adsorption complexes and by P mineralization from organic matter in an Himalayan acid Alfisol.     

Influence of AM fungi,inorganic phosphorus and irrigation regimes on plant water relations and soil physical properties in okra (Abelmoschus esculentus L.) – pea (Pisum sativum L.) cropping system in Himalayan acid alfisol

Present investigation studied plant water relations and soil physical properties through AM fungi (Glomus mosseae) to mitigate drought stress in Himalayan acid Alfisol having low water retentivity. Experimentation was carried out at Palampur, India during 2009–2011 in okra–pea cropping system in randomized block design (RBD) replicated thrice with 14 treatments comprising arbuscular mycorrhizal (AM) fungi, varying phosphorus nutrition and irrigation regimes at 40 and 80% available water holding capacity. Integrated use of AM fungi at varying phosphorus (P) levels and irrigation regimes led to significantly higher relative leaf water content (3% each) in okra and pea besides significantly higher xylem water potential (27%) in pea over non-AM fungi counterparts. AM fungi enhanced water-use-efficiency in okra (5–17%) and pea (12–35%) over non–AM fungi counterparts. AM fungi also improved water holding capacity (5–6%) and mean weight diameter of soil particles (4–9%) over non–AM fungi counterparts; but, had nominal or no effect on bulk density. Mycorrhizal plants maintained higher tissue water content imparting greater drought resistance to plants over non–mycorrhizal plants at moisture stress. It is inferred that integrated application of AM fungi and P at varying irrigation regimes improved the plant water relations vis-à-vis drought resistance, crop productivity, WUE, soil aggregation and water holding capacity in okra–pea sequence in Himalayan acid Alfisol.     

Effect of Phosphorus Additions and Arbuscular Mycorrhizal Fungal Inoculation on the Growth,Physiology, and Phosphorus Uptake of Wheat Under Two Water Regimes

Drought stress greatly affected the growth and development of wheat in the world, while wheat growth could benefit through improvement of water status and nutrient uptake by mycorrhizal symbiosis or addition of phosphorus (P). Experimental treatments were (a) phosphorus addition (0 and 90 kg/ha), (b) soil water condition (40% field capacity and 95% field capacity), and (c) arbuscular mycorrhizal fungi (AMF, Glomus intraradices) (noninoculation and inoculation) which were conducted in a growth chamber. The results showed that addition of phosphorus and AMF inoculation significantly increased the relative water content and specific leaf area of flag leaves especially under 40% field capacity (water deficit (WD)). The leaf gas exchange parameters were all decreased under WD. The water use efficiency (WUE) and instantaneous WUE (WUEi) was enhanced by WD, AMF inoculation, and phosphorus addition. AMF inoculation and WD significantly decreased the carbon isotope discrimination (CID) of leaf. The P concentrations in stem, grain, and leaf were significantly increased by phosphorus addition, WD, and AMF inoculation. Significant correlations were found between WUE and grain P, stem P, and leaf P concentrations. Leaf CID was significantly negatively correlated with WUE and stem P concentrations. Inoculation of AMF or phosphorus addition could improve the growth, physiology, and phosphorus uptake in spring wheat under drought conditions.     

Tripartite symbiosis of Pisum–Glomus–Rhizobium leads to enhanced productivity,nitrogen and phosphorus economy,quality, and biofortification in garden pea in a Himalayan acid Alfisol

The present study was carried out to assess nitrogen (N) and phosphorus (P) economy, quality, and productivity of garden pea (Pisum sativum L.) through dual-inoculation of arbuscular mycorrhizal fungi (AMF) and Rhizobium in an acid Alfisol. Experiment was laid out in randomized block design replicated thrice comprising 13 treatments viz. Rhizobium along with three graded N levels (25%, 50%, and 75% soil-test-based recommended N), AMF along with three graded P levels (25%, 50%, and 75% soil-test-based recommended P), dual-inoculation of AMF and Rhizobium conjoint with four graded N and P levels (25%, 50%, 75%, and 100% soil-test-based recommended N and P), and three other treatments viz. generalized recommended NP potassium (K) dose (GRD), farmers' practice, and absolute control. The results revealed that dual-inoculation of AMF and Rhizobium enhanced the pea productivity, macronutrient (NPK) and micronutrient iron, copper, zinc, and manganese (Fe, Cu, Zn, and Mn) concentrations, and their uptake besides enhancing garden pea quality. Also, dual-inoculation of both symbionts at 75% and 100% soil-test-based N and P dose behaved statistically alike with respect to pea pod yield, NPK uptake, and quality parameters like total soluble solids (TSS) and crude protein (CP), thus indicating an economy of about 25% soil-test-based N and P dose through co-inoculation. AMF and Rhizobium dual-inoculated treatments led to enhanced TSS and CP in pea pods by 4.2% and 6.2%, respectively, over GRD, while sole application of AMF- or Rhizobium-imbedded treatments could enhance these quality parameters by 2.1% only in each case. Similarly, the highest N and P response ratio was registered in dual-inoculated treatments. Overall, dual-inoculation of AMF and Rhizobium with 75% soil-test-based N and P dose in pea can save up to 25% fertilizer N and P dose in acid Alfisol.Also, this tripartite symbiosis besides enhancing pea quality led to better bio-fortified pea seeds with micronutrients especially Fe and Zn, which can greatly curtail the widespread anemia and Zn deficiency in humans living in Himalayan acid Alfisol.     

Pomegranate Growth Affected by Arbuscular Mycorrhizae,Phosphorus Fertilizer,and Irrigation Water Salinity

Pomegranate (Punica granatum L.) symbiosis with arbuscular mycorrhizae fungi (AMF) is a strategy in saline soils. In this study, two AMF (+AMF and –AMF), two phosphorus (P) fertilizer (+ P and –P), and three irrigation salinity (1, 4, and 8 dS m^?1) treatments were studied. The highest salinity level decreased the root colonization by hyphae. Plant growth parameters including shoot dry weight, leaf surface area, and plant height were negatively affected by salinity. However, the growth parameters improved in AMF treatments. Salinity decreased the shoot P concentration and increased the shoot chlorine (Cl). The root and shoot sodium (Na) concentrations were the greatest in unfertilized and P-fertilized treatments, respectively. AMF treatment improved the root and shoot P concentration and reduced the negative effect of salinity on shoot Cl concentrations. In conclusion, the effects of AMF symbiosis on growth and tissue elements concentration depend on irrigation water salinity and P fertilization.     

Productivity,Quality and Soil Health as Influenced by Organic,Inorganic and Biofertilizer on Field Pea in Eastern Himalaya

A field experiment was conducted during two consecutive years of 2010–2011 and 2011–2012 to study the effect of biofertilizers in conjunction with organic and inorganic sources of nutrient management on productivity, quality and soil health on field pea at ICAR RC for NEH Region, Nagaland Centre Jharnapani, Nagaland, India. The experiment was laid out in split plot design with five nutrient sources in main plots and four treatment of biofertilizers with zinc in sub plots. Results indicated that the application of 100% recommended dose of fertilizer (RDF) through inorganic + 50% recommended dose of nitrogen (RDN) through vermicompost significantly improved root nitrogen (N) content, cation exchange capacity (CEC) of roots, NA activates, seed yield (1153 and 1262 kg ha^?1), straw yield (2182 and 2332 kg ha^?1) in the year of 2010–2011 and 2011–2012, respectively. Nutrients (N, P, K, S and Zn) uptake by seed and straw, protein content, protein harvest, soil organic carbon (SOC), available N, P, K, S, Zn and economics significantly higher with 100% RDF through inorganic + 50% RDN through vermicompost during both the years. Seed inoculation with biofertilizers along with 5 kg Zn ha^?1 markedly enhanced the root N content, CEC of roots, nitrogenase activities (NA), seed yield (1080 and 1193 kg ha^?1), straw yield (1978 and 2128 kg ha^?1), nutrients [N, phosphorus (P), potassium (K), sulfur (S) and zinc (Zn)] uptake, soil organic carbon (SOC) (%), and available N, P, K, S, and Zn of pea in both the years, respectively. These sources also give more income and benefit cost ratio per rupees invested.     

外源磷与AMF对间作玉米种植红壤无机磷形态的影响

通过三室隔网分室盆栽模拟试验,研究了分室不同磷(P)源[无机磷(磷酸二氢钾)和有机磷(大豆卵磷脂),P添加量均为50 mg·kg-1]添加和根室接种不同丛枝菌根真菌(AMF)[Glomus mosseae(GM)、Glomus etunicatum(GE)]对间作玉米种植红壤无机磷形态的影响。结果表明:无论接种与否,间作处理使根室土壤有效磷含量显著降低,说明间作能够促进玉米植株对土壤有效磷的吸收,且有效磷的耗竭从根际土壤开始。除OP50-单作玉米处理的Org-P外,接种AMF均一定程度增加了各形态无机磷含量。此外,根室土壤有效磷的主要组分为Ca2-P、Al-P和Org-P,其中Org-P与土壤有效磷有着极显著的负相关关系。     

低磷土壤接种菌根真菌和解磷细菌对大田玉米生长和磷吸收的影响

丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)能与多数陆生植物共生,促进植物吸收养分尤其是磷。解磷细菌(Phosphate-solubilizing bacteria,PSB)可以活化土壤中难溶性无机磷和有机磷。本研究采用苯菌灵对田间低磷土壤中土著AM真菌进行灭菌,并接种外源AM真菌(Glomusversiforme,G.v)和PSB(Pseudomonassp.),研究AM真菌和PSB接种对不同生育期玉米生长、磷养分吸收和产量的影响。结果表明,施用苯菌灵能够有效地抑制土著AM真菌对玉米根系的侵染,未施用苯菌灵处理中土著AM真菌促进了玉米前期和收获期的生长,提高了玉米吸磷量;接种Pseudomonas sp.促进了玉米六叶期根系的生长;接种外源AM真菌G.v促进了玉米六叶期和收获期地上部的生长,但降低了玉米产量。双接种Pseudomonas sp.和G.v对玉米生长、吸磷量和产量未表现出显著的协同效应。     

施磷水平和接种AMF与解磷细菌对苜蓿产量及磷素利用效率的影响

为探讨不同施磷水平下接种丛枝菌根真菌（Arbuscular Mycorrhizae Fungi，AMF）与解磷细菌对苜蓿干物质产量及其磷素利用效率的影响，筛选出苜蓿最佳的施肥模式，为紫花苜蓿高效生产及高效复合型菌肥的研制提供理论依据。该研究试验采用双因素随机区组设计，AMF选用摩西管柄囊霉，解磷细菌选用巨大芽孢杆菌，设置4个施菌水平：分别为接种摩西管柄囊霉（Fm，J1）、巨大芽孢杆菌（Bm，J2）、混合菌种（Fm×Bm，J3）和未接菌处理对照组（J0）。施磷（P2O5）设置4个水平P0~P3分别为：0、50、100和150 mg/kg，菌磷互作共16个处理。结果表明：1）相同施菌条件下，苜蓿各茬次干物质产量、总干物质产量和植株磷含量均随施磷量的增加呈先增加后降低的趋势。除J2条件下，J2P1处理下的苜蓿总干物质产量达到最大值外，其他施菌条件下，苜蓿的总干物质产量均在P2处理达到最大，且施磷处理显著大于未施磷处理（P<0.05）。苜蓿的磷肥偏生产力及磷肥农学效率均随施磷量的增加呈逐渐降低的趋势，而土壤全磷含量和速效磷含量均随着施磷量的增多呈增加的趋势。2）相同施磷处理下，单接种菌处理和混合接种处理下苜蓿的干物质产量、植株磷含量、磷素利用效率、土壤全磷以及速效磷含量均显著大于不接菌处理（P<0.05），其中总干物质产量、土壤全磷和速效磷含量均在J3处理达到最大值。根际土壤速效磷含量与干物质产量拟合的相关系数最大，拟合效果最好。土壤全磷、速效磷含量均与总干物质产量呈显著正相关。因此，当施磷量为100 mg/kg，混合接种AMF与解磷细菌能够显著增加苜蓿土壤磷素有效性，提高磷素利用效率，进而增加苜蓿的干物质产量。     

分室磷添加下菌根对滇池流域红壤间作玉米生长及磷素利用的影响

随着全球范围内磷矿资源短缺问题的日益严重,间作或菌根技术强化作物对土壤磷(P)的利用及增产增收的效应受到越来越多的关注。通过三室隔网盆栽模拟试验研究了分室磷处理[不添加磷(P0)、添加有机磷(OP50)、添加无机磷(IOP50)]和根室不接种(NM)、根室接种丛枝菌根真菌Glomus mosseae(GM)对与大豆间作的玉米的生长及磷素利用的影响。研究结果表明:所有复合处理中,以间作?GM?IOP50组合处理下的玉米根系最短和地上部生物量最高;OP50处理下,间作玉米的菌根侵染率显著高于单作处理。间作条件下,无论分室磷添加与否,接种GM处理的玉米地上部生物量明显高于NM处理;接种GM处理的玉米根系生物量和株高均显著高于NM处理,且根系生物量以间作?GM?OP50组合处理下最高。接种GM条件下,P0、IOP50、OP50处理下的间作植株生物量较单作处理分别提高45.98%、111.33%、33.56%。单作条件下,无论分室磷添加与否,接种GM处理的玉米地上部磷含量均显著高于NM处理;无论何种种植模式及分室磷添加与否,接种GM处理的植物根系磷含量均显著高于NM处理。无论磷添加与否,间作?GM组合条件下的玉米地上部磷吸收量均显著较高,其中IOP50处理下的地上部磷吸收量显著高于OP50处理。间作?GM组合条件下,IOP50处理玉米根系的磷吸收效率均显著高于OP50处理。可见,接种GM、分室磷添加和间作各自在一定程度上促进了玉米的生长。综合菌根侵染、生物量及磷含量与吸收量、磷吸收效率等指标,所有复合处理中以间作?GM?IOP50组合对玉米地上部的促生作用最好,玉米磷素吸收最多,可望有效强化滇池流域红壤坡耕地磷素的利用。     

The effect of mycorrhizal inoculation and phosphorus application on the growth and mineral nutrient status of apple seedlings

Apple seedlings cv. Antonovka were grown in soil taken from an orchard with a distinctive specific apple replant disease. The influence of the different available soil phosphorus (P) level (0, 20, 40 and 80 mg P dm^?3 of soil) and arbuscular mycorrhizae fungi (AMF) inoculation on the vegetative growth, chlorophyll fluorescence, and the frequency of mycorrhizae were assessed. Moreover, leaf and root mineral composition was ascertained by means of the inductively coupled plasma mass spectrometry (ICP-MS) method. The inoculation with AMF influenced seedlings growth as well as the biomass production and partitioning. The method of inoculation (granular, quick root dip or irrigation) had a great impact on the frequency of mycorrhizae (83.3, 98.8 and 100%, respectively) as well as on the abundance of arbuscules (36.4, 62.9 and 67.3%) as compared to the control (11.7%). The beneficial effect of AMF on leaf PSII efficiency was established. AMF inoculated plants had a significantly higher content of nitrogen, potassium, phosphorus and boron (N, K, P and B) in the shoots and a higher content of nitrogen, sulfur, copper, iron, manganese, molybdenum and titanium (N, S, Cu, Fe, Mn, Mo and Ti) in the roots. Although roots showed a higher concentration of aluminium, barium, lithium, cadmium, lead and vanadium (Al, Ba, Li, Cd, Pb, and V) but upon AMF inoculation, the concentration of these cations was much lower.     

Performance of Turmeric and Soil Moisture Depletion Pattern Under Different Water Regimes and Nutrient Sources at New Alluvial Zone of Indo-Gangetic Plains,India

In India, the production of turmeric is not even half compared to its potential. To analyze the possibilities for higher production in turmeric, this study was conducted at the BCKV, Gayeshpur, West Bengal, during 2011 and 2012, to evaluate the effect of irrigation scheduling (0.6, 0.9, and 1.2 irrigation water (IW)/cumulative pan evaporation (CPE) and rainfed) in main plots and nutrient management [100% inorganic, 75% inorganic + 25% FYM (Farm yard manure), and 50% inorganic + 25% FYM + 25% vermicompost] in subplots on soil moisture depletion and productivity of turmeric. The highest value of fresh rhizome yield (23.90 kg ha^?1) and qualitative indices were obtained with irrigation schedule at 0.9 IW/CPE ratio water regimes and 50% inorganic + 25% FYM + 25% vermicompost. The correlation coefficients of water use and yield of turmeric were found at 0.943. The combination of 0.9 IW/CPE and 50% inorganic + 25% FYM + 25% vermicompost improved the overall performance of turmeric crop.     

不同施磷水平下灌水量对小麦水分利用特征及产量的影响

采用大田试验,设灌水和施磷2个因素,其中灌水设W0(不灌水)、W1(拔节水60mm)、W2(拔节水+开花水,每次灌水60mm)、W3(拔节水+开花水+灌浆水,每次灌水60mm)共4个水平;磷肥设P1(90kg/hm2)和P2(180kg/hm2)2个水平,研究不同施磷水平下灌水量对小麦耗水特征、旗叶水分生理特性及产量的影响。结果表明:同一施磷水平下,随灌水量的增加,灌水量占总耗水量的比例增大,而降水量和土壤供水量所占总耗水量的比例下降,且土壤供水量占总耗水量的比例降低幅度增大。与P1相比,P2处理的0-100cm土壤贮水消耗量显著大于P1处理,并且P2处理提高土壤供水量占总耗水量的比例,说明增施磷肥可提高小麦对土壤水的利用。W2和W3处理灌浆中后期旗叶相对含水量和水势高于W0和W1处理;灌浆后期旗叶相对含水量和水势为P2W0和P2W1处理显著分别高于P1W0和P1W1处理,说明增加灌水和磷肥能显著提高旗叶水势和相对含水量。在本试验条件下,施磷90kg/hm2、拔节水和开花水分别灌60mm的W2处理籽粒产量、水分和磷素利用效率高,农田耗水量较低;增加灌水量后籽粒产量无显著变化,农田耗水量增高,土壤贮水消耗量、水分利用效率、灌溉水利用效率均降低。     

MYCORRHIZAL INFLUENCE ON FRUIT YIELD AND MINERAL CONTENT OF TOMATO GROWN UNDER SALT STRESS

Tomato (Lycopersicon esculentum Mill.) yields are known to decrease for plants grown in saline soils. This study was conducted to determine the effects of arbuscular mycorrhizal fungi (AMF) inoculation on fruit yield and mineral content of salt-tolerant and salt-sensitive tomato cultivars grown with varied levels of salt. NaCl and CaCl₂were added to soil in the irrigation water in equal molar ratios to give EC_e values of 1.4 (nonstressed) and 4.9 dS m^?1 (salt stressed). Plants were grown in a greenhouse using unsterilized, low phosphorus (P) (silty clay) soil-sand mix. Mycorrhizal root colonization occurred whether cultivars were salt stressed or nonstressed, but the extent of AMF root colonization was higher in AMF inoculated than uninoculated plants. The salt tolerant cultivar ‘Pello’ generally had higher AMF root colonization than the salt sensitive cultivar ‘Marriha’. Shoot dry matter (DM) yield, fruit fresh yield, and AMF colonization were higher for plants grown under nonstressed than for plants grown under salt stressed conditions. Shoot DM and fruit fresh yields were higher in AMF inoculated than uninoculated plants grown with or without salt stress. Pello generally had higher fruit fresh yield per plant and fruit weight than Marriha, but these differences were only significant for fruit weight in unioculated plants grown under salt stressed conditions. The enhancement in fruit fresh yield due to AMF inoculation was 26 and 23% under nonstressed and 28 and 46% under salt stressed treatments for Pello and Marriha, respectively. For both cultivars, fruit contents of P, potassium (K), zinc (Zn), copper (Cu), and iron (Fe) were higher in AMF inoculated compared with uninoculated plants grown under nonstressed and salt stressed conditions. Fruit Na concentrations were lower in AMF inoculated than uninoculated plants grown under salt stressed conditions. The enhancement in P, K, Zn, Cu, and Fe acquisition due to AMF inoculation was more pronounced in Marriha than in Pello cultivar under salt stressed conditions. The results of this study indicated that AMF inoculated plants had greater tolerance to salt stress than unioculated plants.