Response of maize (Zea mays) to the application of foliar fertilizers in the Sudan and Guinea savanna zone of Nigeria

Soil fertility problems resulting in low maize yields in smallholder farms are common in the West African moist savanna. The effectiveness of commercial foliar fertilizers in improving maize growth and yield was evaluated in three savanna agro‐ecological zones of Nigeria in two steps. In step one, eight commercial foliar fertilizers were assessed in a greenhouse study with two soil types using maize (Zea mays L. cv. 2004 TZE‐Y POPDT STR C4). The treatments included a control and a reference that received the optimum concentrations of nutrients. In step 2, three promising products from the greenhouse study (Turbotop, Agroleaf General, and Agroleaf high‐P) were evaluated under field conditions to validate the efficacy of products to enhance crop growth and yield. The foliar products were applied at the rate of 5 kg ha^?1. The treatments also included three rates of P application (0, 30, and 60 kg P ha^?1) as triple super phosphate (TSP) with or without foliar fertilizers. In the greenhouse study, differences in maize shoot dry matter yield and N and P concentrations, attributable to the spraying of the commercial foliar fertilizers, were observed for both soils. Spraying Turbotop, Agroleaf General, and Agroleaf high‐P gave the highest shoot dry biomass and N and P uptake compared to other products. Under field conditions, foliar spraying of Agroleaf high‐P significantly increased the shoot dry biomass of maize compared with the 0 P treatment in all locations. The grain yield of maize ranged from 1 to 4 t ha^?1 with significant differences across sites. Products with high concentrations of P and N in their formulation improved maize yield suggesting that appropriate management of P and N resources is a prerequisite for a sustainable maize intensification in the savanna agro‐ecologies.     

Assessment of nitrogen uptake and utilization in drought tolerant and Striga resistant tropical maize varieties

Maize (Zea mays L.) is an important food crop in the Guinea savannas of Nigeria. Despite its high production potential, drought, Striga hermonthica parasitsim, and poor soil fertility particularly nitrogen deficiency limit maize production in the savannas. Breeders at IITA have developed drought- and Striga-tolerant cultivars for testing, dissemination, and deployment in the region. Information on the response of these cultivars to N fertilization is, however, not available. This study evaluated grain yield, total N uptake (TNU), N uptake (NUPE), N utilization (NUTE), and N use efficiency (NUE) of selected maize cultivars along with a widely grown improved maize cultivar at two locations in the Guinea savannas of northern Nigeria. Maize grain yield increased with N application. The average grain yield of the maize cultivars was 76% higher at 30, 156% higher at 60, and 203% higher at 120 kg N ha^?1 than at 0 kg N ha^?1. This suggests that N is a limiting nutrient in the Nigerian savannas. Five drought-tolerant cultivars produced consistently higher yields when N was added at all levels. These cultivars had either high NUPE or NUTE confirming earlier reports that high N uptake or NUTE improves maize grain yield. The study also confirms earlier reports that maize cultivars that are selected for tolerance to drought are also efficient in uptake and use of N fertilizer. This means that these cultivars can be grown with application of less N fertilizer thereby reducing investment on fertilizers and reduction in environmental pollution.     

长期定位试验中氮肥与磷肥有机肥联合施用通过刺激根的生长增加玉米产量和养分吸收

Imbalanced application of nitrogen (N) and phosphorus (P) fertilizers can result in reduced crop yield, low nutrient use efficiency, and high loss of nutrients and soil nitrate nitrogen (NO₃^--N) accumulation decreases when N is applied with P and/or manure; however, the effect of applications of N with P and/or manure on root growth and distribution in the soil profile is not fully understood. The aim of this study was to investigate the combined effects of different N and P fertilizer application rates with or without manure on maize (Zea mays L.) yield, N uptake, root growth, apparent N surplus, Olsen-P concentration, and mineral N (Nmin) accumulation in a fluvo-aquic calcareous soil from a long-term (28-year) experiment. The experiment comprised twelve combinations of chemical N and P fertilizers, either with or without chicken manure, as treatments in four replicates. The yield of maize grain was 82% higher, the N uptake 100% higher, and the Nmin accumulation 39% lower in the treatments with combined N and P in comparison to N fertilizer only. The maize root length density in the 30--60 cm layer was three times greater in the treatments with N and P fertilizers than with N fertilizer only. Manure addition increased maize yield by 50% and N uptake by 43%, and reduced Nmin (mostly NO₃^--N) accumulation in the soil by 46%. The long-term application of manure and P fertilizer resulted in significant increases in soil Olsen-P concentration when no N fertilizer was applied. Manure application reduced the apparent N surplus for all treatments. These results suggest that combined N and P fertilizer applications could enhance maize grain yield and nutrient uptake via stimulating root growth, leading to reduced accumulation of potentially leachable NO₃^--N in soil, and manure application was a practical way to improve degraded soils in China and the rest of the world.     

Improved productivity and zinc content for maize grain by different zinc fertilization techniques in calcareous soils

Scientific management of nutrients along with several other crop management practices are required for sustainable production of maize (Zea mays L.). Zinc (Zn) status of maize grown in Potohar plateau, Pakistan was monitored. A two-year field study was conducted at two sites to assess the yield of maize cultivars, i.e., hybrid (cv. NARC-2704) and local (cv. Agaiti-2002) and Zn requirement of leaves and grain using various Zn application methods. Zinc was applied by three ways, i.e., broadcast and band placement each at 3, 6 and 9 kg Zn ha^?1; and foliar at 0.5, 1.0 and 1.5 kg Zn ha^?1 along with recommended basal fertilization. Cultivars' response varied to Zn rates, application techniques and sites. The maximum increase in grain yield (two-year mean) at NARC site was: broadcast – hybrid, 17% and local, 13%; band placement – hybrid, 18% and local, 16%; and foliar – hybrid, 15% and local, 13%. Corresponding response at Pindi Gheb site was: broadcast – hybrid, 20% and local, 16%; band placement – hybrid, 21% and local, 17%; and foliar – hybrid, 17% and local, 15%. Zn concentration in leaves and grain of both cultivars also increased to varying extent as a result of applied Zn rates and techniques. Fertilizer Zn requirement for near-maximum grain yield (kg ha^?1) was: broadcast – hybrid, 4.6 and local, 1.9; band placement – hybrid, 1.8 and local, 1.5; and foliar – hybrid, 0.28 and local, 0.26.     

Zinc fertilization approaches for agronomic biofortification and estimated human bioavailability of zinc in maize grain

Maize (Zea mays L.) is generally low in bioavailable zinc (Zn); however, agronomic biofortification can cure human Zn deficiency. In the present experiment, Zn was applied in pots as ZnSO₄ · 7H₂O to maize cultivar DK-6142 as foliar spray (0.5% w/v Zn sprayed 25 days after sowing and 0.25% w/v at tasseling), surface broadcasting (16 kg Zn ha^?1), subsurface banding (16 kg Zn ha^?1 at the depth of 15 cm), surface broadcasting + foliar and subsurface banding + foliar in comparison to an unfertilized control. As compared to control, all treatments significantly (P ≤ 0.05) increased growth, yield and nutritional attributes in maize. Grain Zn and protein concentrations were correlated and ranged from 22.3 to 41.9 mg kg^?1 and 9 to 12 %, respectively. Zinc fertilization also significantly reduced grain phytate and increased grain Zn concentration. Zinc fertilization, especially broadcasting and subsurface banding combined with foliar spray decreased grain [phytate]:[Zn] ratio to 28 and 21 and increased Zn bioavailability by trivariate model of Zn absorption to 2.04 to 2.40, respectively. Conclusively, broadcasting and subsurface banding combined with foliar spray is suitable for optimal maize yield and agronomic Zn biofortification of maize grain. This would also be helpful to optimize Zn and protein concentration in maize grain.     

Agronomic evaluation of mulching and iron nutrition on productivity,nutrient uptake,iron use efficiency and economics of aerobic rice-wheat cropping system

Field experiments were carried out during rainy (kharif) and winter (rabi) seasons (June–April) of 2008–2010 at Indian Agricultural Research Institute (IARI), New Delhi, to study the productivity, nutrients uptake, iron (Fe) use-efficiency and economics of aerobic rice-wheat cropping system as influenced by mulching and Fe nutrition. The highest yield attributes, grain and straw yields (5.41 tonnes ha^?1 and 6.56 tonnes ha^?1, respectively) and nutrient uptake in rice was recorded with transplanted and puddled rice (TPR) followed by aerobic rice with Sesbania aculeata mulch. However, residual effect of aerobic rice with wheat straw mulch was more pronounced on yield attributes, grain and straw yields (4.20 and 6.70 tonnes ha^?1, respectively) and nutrient uptake in succeeding wheat and remained at par with aerobic rice with Sesbania mulch. Application of iron sulfate (FeSO₄) at 50 kg ha^?1 + 2 foliar sprays of 2% FeSO₄ was found to be the best in terms of all the yield attributes, grain and straw yield (5.09 and 6.17 tonnes ha^?1, respectively) and nutrient uptake and remained at par with 3 foliar sprays of 2% FeSO₄. Although residual effect of iron application failed to increase the yield attributes, yield and nutrient uptake nitrogen, phosphorus and potassium (N, P, K) except Fe. The highest system productivity, nutrient uptake, gross returns, net returns, B: C ratio and lowest cost of cultivation were recorded with aerobic rice with wheat straw and Sesbania aculeata mulch. Application of FeSO₄ at 50 kg ha^?1 + two foliar sprays of 2% FeSO₄ was found better in respect of system productivity, nutrient uptake, gross returns, net returns, B:C ratio and cost of cultivation in aerobic rice-wheat cropping system. The Fe use efficiency values viz. partial factor productivity (kg grain kg^?1 Fe), agronomic efficiency (kg grain increased kg^?1 Fe applied), agrophysiological efficiency (kg grain kg^?1 Fe uptake), physiological efficiency (kg biomass kg^?1 Fe uptake), apparent recovery (%) utilization efficiency and harvest index (%) of applied Fe were significantly affected due to methods of rice production and various Fe nutrition treatments in aerobic rice and aerobic rice-wheat cropping system.     

Effects of liquid seaweed extracts in improving the agronomic performance of foxtail millet

Abstract

In recent decades, chemical fertilizers create a thread to organic agriculture and food security. To overcome this issue, the present study aimed to investigate the influence of liquid seaweed extracts (LSEs) prepared from Padina boergesenii (PB) and Gracilaria edulis (GE) on growth, development, biochemical characteristics and yield traits of foxtail millet. The various concentrations of individual (20, 40, 60, and 80%; v/v) and combined (10?+?10, 20?+?20, 30?+?30, and 40?+?40%; v/v) PB and GE LSEs were supplied through foliar spray method. The results imply that germination bioassays, vegetative plant growth were significantly increased in lower concentration of LSEs. Further, exposure of foxtail plants to combined foliar spray application of (20?+?20%; v/v) LSEs enriched photosynthetic pigments, total soluble sugar and total soluble protein, compared with single LSEs and control foliar spray methods. Additionally, LSEs enhanced the yield attributes such as the average number of seeds (971.5/panicle) and mean length of panicle (18.4?cm) in PB?+?GE LSEs (20?+?20%; v/v) treatment. This is the first report, to assess the synergistic biostimulant ability of PB and GE LSEs in plant growth, quality improvement and yield attributes of foxtail millet. In conclusion, this present study suggests that combination of PB?+?GE LSEs foliar spray application could serve as an ideal biostimulant and a potential alternate to hazards chemical fertilizer in the green agriculture.     

Foliar calcium spray confers drought stress tolerance in maize via modulation of plant growth,water relations,proline content and hydrogen peroxide activity

Water and nutrient restrictions are the factors that limiting growth of maize in arid/semi-arid climate. Calcium (Ca²⁺) uptake is affected severely under drought stress (DS). The objectives of this study were to investigate the effects of DS and foliar applied Ca²⁺ on growth, physiological, biochemical, yield and grain-nutrient content in two maize cultivars i.e. drought-tolerantDekalb-6525 and drought-sensitive Yousafwala-hybrid. The study comprised of two phases; firstly the best rate of Ca²⁺ (20, 40 and 60 mg L?1) was evaluated. Secondly, optimized rate of Ca²⁺ (40 mg L?1) was used to assess physio-biochemical and yield responses of maize under DS. The applied DS caused significant reduction in maize growth, water-status, photosynthesis and grain nutrient contents. Foliar Ca²⁺ markedly improved plant growth, water-potential (18%), turgor-potential (75%), photosynthesis (45%), stomatal-conductance (47%), transpiration rate (43%) and accumulation of total soluble sugars (20%) along with decline in H2O2 content (23%) in both cultivars under DS. Furthermore, optimized rate of Ca²⁺ improved maize grain yield and quality under water-deficit conditions. Cultivar Dekalb-6525 presented significant response to Ca²⁺ over Yousafwala-hybrid. Results of the study surmise that foliar supply of Ca²⁺ is an effective approach to make plants vigorous to thrive under limited-water supply.     

种植方式对玉米大豆套作体系中作物产量、养分吸收和种间竞争的影响

为探寻玉米-大豆套作体系下作物间的资源竞争关系,揭示玉米-大豆套作系统的增产机理,本研究以玉米-大豆套作系统(简称玉豆套作)为对象,通过2 a大田定位试验,研究了玉豆套作带状连作(A1)、玉豆套作带状轮作(A2)、玉豆套作等行距种植(A3)、玉米单作(A4)、大豆单作(A5)5种种植方式对玉米、大豆的产量、养分吸收及种间竞争能力的影响。结果表明,与单作和等行距种植相比,带状种植的玉米产量降低、大豆产量显著增加,A2的大豆产量分别比A5和A3高25.5%和89.2%。与带状连作相比,带状轮作促进玉米增产和对N、P、K的吸收,玉米籽粒产量及植株N、P、K的吸收总量分别提高7.5%、18.5%、9.1%、14.1%。与大豆单作相比,带状套作显著增加了大豆的经济系数和养分收获指数,A2的经济系数和植株N、P、K收获指数分别增加40.9%、11.9%、20.6%、39.9%。带状种植方式下,玉米对N、P、K的竞争力弱于大豆(Ams0,CRms1),但带状轮作提高了玉米的种间竞争力和营养竞争比率。玉米-大豆套作体系下,相对带状连作和等行距种植,带状轮作种植有利于玉米与大豆间的和谐共生,促进了玉米、大豆对养分的吸收,提高了系统的产量和土地当量比率(LER)。     

Methods to investigate fertilization as a means to improve growth and sugar yield of sugar maple

Abstract

In a randomized block experiment, NPKCa fertilizers were applied annually for 5 years to a mature sugar maple (Acer saccharum Marsh.) woodlot in southern Ontario. Trees selected from 3 crown classes were fitted with dendrometer bands, tapped for sap and analyzed for foliar starch and nutrients and sap nutrients. Crown classes responded differently to the fertilizers. Trees which responded significantly in diameter growth did not respond the most in sugar yield. Effects of the fertilizer treatments on sugar yield were shown to be significant when the area of crown overlap of competing trees was subtracted from the crown area of crop trees. Foliar analysis and DRIS showed which nutrients were in demand after fertilizer applications. Sap analysis showed significant relations between sap nutrients and between sap nutrients and diameter growth. Starch analysis showed significantly higher foliar starch concentrations after potassium fertilization than after other fertilizer treatments.     

Effects of Nitrogen and Phosphorus Fertilizers and Intercropping on Uptake of Nitrogen and Phosphorus by Wheat,Maize, and Faba Bean

Abstract

One‐third of all the cultivated land area is used for multiple cropping and half of the total grain yield is produced with multiple cropping in China. There have been numerous studies on nutrient acquisition by crops in legume/non‐legume intercropping systems, but few on nutrient uptake in cereal/cereal intercropping. This paper describes a field experiment in which integrated wheat/maize and maize/faba bean systems were compared with sole wheat and sole faba bean cropping to assess the effects of intercropping on nutrient uptake by wheat, maize, and faba bean under various application rates of nitrogen (N) and phosphorous (P) fertilizers. Results show that both N and P fertilizers and intercropping enhanced N uptake by wheat, while only P fertilizer and intercropping increased P acquisition by wheat. The advantage of N uptake by border rows of wheat intercropped with maize declined with increasing N fertilizer application rate, but that of P acquisition was not affected by P fertilizer. The amounts of both N and P taken up by maize intercropped with faba bean were much higher than those by maize intercropped with wheat throughout the period of intercropping. Both fertilization and intercropping did not influence the N and P uptake by faba bean.     

Nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide and inorganic nitrogen application rates in a derived savanna

Abstract

Field experiments were conducted to investigate nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide (CaC₂) and nitrogen (N) rates in a derived Savanna (2016 and 2017). Maize cultivars {SUWAN-I [open pollinated variety (OPV)] and OBA SUPER II (hybrid)}, rates of N (0, 60 and 90?kg ha^?1) and CaC₂ (0, 30 and 60?kg ha^?1), were arranged in split-split plot respectively, fitted into a randomized complete block design in three replicates. N Partial factor productivity (PFP_N), Agronomic Use Efficiency (both years) and Apparent recovery of N (2017) increased in the order 60?>?90?>?0?kg N ha^?1, except N Internal use efficiency which was in the order 0?>?60?>?90?kg N ha^?1 (2017). Grain yield increased with increasing rates of N in both years. OBA SUPER-II had significantly higher grain yield than SUWAN-I (2017). Similar pattern was observed on number of grains per cob, dry cob weight, PFP_N and plant height (2017). Conversely in 2016, grain, total and shoot N uptakes were significantly higher in SUWAN-I than OBA SUPER-II. Increasing application of CaC₂ increased grain N uptake and number of grains per cob. Number of leaves and stem girth increased in the order of 60?>?0?>?30?kg?CaC₂ ha^?1. Increased grain yield with N rates could be associated with NHI and N use efficiency. These evidences suggested that hybrid maize performed better than OPV in a derived Savanna.     

Increased yield of direct seeded rice (Oryza sativa L.) by foliar fertilization through multi-component fertilizers

Foliar application of fertilizers can guarantee the availability of nutrients to rice for obtaining higher yield. Rice responds favorably to macro- and micronutrients and the tolerance to salinity hazards improves by decreasing the N/S ratio. In this study, results showed that nutrient concentrations (g L^?1) for rice are: nitrogen (N) 108.0, phosphorous (P₂O₅) 6, potassium (K₂O) 81.0, calcium (CaO) 15.0, and magnesium (MgO) 6 g L^?1; and for iron (Fe), manganese (Mn), zinc (Zn), cupper (Cu), boron (B), molybdenum (Mo) and silicon (Si) the recommended concentrations are 0.6, 0.45, 0.21, 0.06, 0.09, 0.0002 and 0.004 g L^?1, respectively. A significant increase was recorded in number of panicles m^?2, 1000 grain weight, biological yield and grain yield with foliar application of nutrients. Five foliar applications of nutrients resulted in maximum number of panicles m^?2, grains panicle^?1, 1000 grain weight and biological yield. It is concluded that five foliar applications of balanced amounts of fertilizers at the seedling stage (two sprays), tillering (single spray) and at panicle initiation and panicle differentiation (two sprays) helped in enhancing yield and yield components of rice. In this research, five foliar applications produced the smallest damaging effects of blast (Pyricularia oryzae) in rice.     

Film fully-mulched ridge-furrow cropping affects soil biochemical properties and maize nutrient uptake in a rainfed semi-arid environment

Abstract

This study evaluated the effects of plastic mulched ridge-furrow cropping on soil biochemical properties and maize (Zea mays L.) nutrient uptake in a semi-arid environment. Three treatments were evaluated from 2008 to 2010: no mulch (narrow ridges with crop seeded next to ridges), half mulch (as per no mulch, except narrow ridges were mulched), and full mulch (alternate narrow and wide ridges, all mulched with maize seeded in furrows). Compared to the no mulch treatment, full mulch increased maize grain yield by 50% in 2008 and 25% in 2010, but reduced yield by 21% in 2009 after low precipitation in early growth. Half mulch had a similar grain yield to no mulch in the three cropping years, suggesting half mulch is not an effective pattern for maize cropping in the area. Mulch treatments increased aboveground nitrogen (N) uptake by 21?34% and phosphorus (P) uptake by 21?42% in 2008, and by 16?32% and 14?29%, respectively, in 2010; but in 2009 mulching did not affect N uptake and decreased P uptake. Soil microbial biomass and activities of urease, β-glucosidase and phosphatase at the 0?15 cm depth were generally higher during vegetative growth but lower during reproductive growth under mulch treatments than no mulch. Mulching treatments increased carbon (C) loss of buried maize residues (marginally by 5?9%), and decreased light soil organic C (15?27%) and carbohydrate C (12?23%) concentrations and mineralizable C and N (8?36%) at harvest in the 0?20 cm depth compared with no mulch, indicating that mulching promotes mineralization and nutrient release in soil during cropping seasons. As a result of these biological changes, mineral N concentration under mulch was markedly increased after sowing in upper soil layers compared with no mulch. Therefore, our results suggest that mulched cropping stimulated soil microbial activity and N availability, and thus contributed to increasing maize grain yield and nutrient uptake compared with no mulch.     

Bacterial inoculants for rice: effects on nutrient uptake and growth promotion

Beneficial soil bacteria are able to colonize plant root systems promoting plant growth and increasing crop yield and nutrient uptake through a variety of mechanisms. These bacteria can be an alternative to chemical fertilizers without productivity loss. The objectives of this study were to test bacterial inoculants for their ability to promote nutrient uptake and/or plant growth of rice plants subjected to different rates of chemical fertilizer, and to determine whether inoculants could be an alternative to nitrogen fertilizers. To test the interaction between putatively beneficial bacteria and rice plants, field experiments were conducted with two isolates: AC32 (Herbaspirillum sp.) and UR51 (Rhizobium sp.), and different nitrogen fertilization conditions (0%, 50%, and 100% of urea). Satisfactory results were obtained in relation to the nutrient uptake by plants inoculated with both isolates, principally when the recommended amount of nitrogen fertilizer was 50% reduced. These bacterial strains were unable to increase plant growth and grain yield when plants were subjected to the high level of fertilization. This study indicated that the tested inoculant formulations can provide essential nutrients to plants, especially when the levels of nitrogen fertilizers are reduced.     

Response of maize (Zea mays) to Azotobacter inoculation under fertilized and unfertilized conditions

Summary Inoculated seeds of maize (Zea mays) with 11 Azotobacter strains, sown in the fields receiving no fertilizer and fertilizers (N and P at the rate of 125 and 40 kg ha^–1 respectively) increased the grain yield by 19.63% and 15.89% respectively over the corresponding control. The effect was greater in unfertilized than in fertilized soil. The increase in yield due to fertilizers was 21.2% without inoculation and 37.09% with inoculation. The correlations between total yield, and N, P and K uptake were highly significant and comparable among themselves. This indicated that increase in yield due to inoculation was not due to N₂ fixation but that some other mechanisms like production of growth hormones by this bacterium may be responsible.     

Biomass accumulation and N status in grain maize as affected by mineral and organic fertilizers in cool climate

Abstract

Expansion of grain maize to marginally suitable cool climate regions requires a better understanding of the nitrogen (N) economy of the crop. This study was aimed at yield formation in response to different type of fertilizers. Field experiments with short-season maize variety were conducted in Akademija, Lithuania, in 2015 and 2016. In spring, before sowing, ammonium nitrate, pelletized cattle and poultry manures, green waste compost were incorporated at a rate equivalent to 170?kg N ha^?1. Crop N status, based on SPAD measurements, started to differ significantly at the end of the vegetative period with higher values in treatments applied with ammonium nitrate and lower with organic fertilizers. Under favorable conditions maize produced more grain per cob and higher yield. Agronomic N use efficiency (AE_N) of pelletized organic fertilizers in the unfavorable season (AE_N 2015: 0.1–4.9) was poor and significantly lower than in the favorable season of (AE_N 2016: 4.9–11.2).     

Enhancing nutrient translocation,yields and water productivity of wheat under rice–wheat cropping system through zinc nutrition and residual effect of green manuring

Abstract

Efficient nutrient and water use are two important considerations to obtain good harvests of wheat. This necessitates the development of an effective nutrient management technique that not only increases yield, but simultaneously can save nutrient and water use. In this context, a field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India to evaluate the residual effect of sesbania and rice bean (in-situ), subabul (ex-situ) green manuring and Zinc (Zn) fertilization, using chelated Zn-ethylenediaminetetraacetic acid (Zn-EDTA) on nutrient use, yields and water productivity of wheat under rice–wheat cropping system. Among residual effects of green manure crops and Zn fertilization, sesbania and foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 days after sowing (DAS) recorded significantly higher nutrient content and uptake and yields than other green manure crops and Zn treatments. Residual effect of sesbania saved about 46.5?×?10³ and 30.5?×?10³ L irrigation water per tonne of wheat over subabul and rice bean, respectively. Foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 DAS saved about 55.5?×?10³, 47?×?10³ and 13?×?10³ L irrigation water per tonne wheat over residual effect of 5?kg Zn ha^?1 through chelated Zn-EDTA as soil application, 2.5?kg Zn ha^?1 through chelated Zn-EDTA as soil application + 1 foliar spray of 0.5% chelated Zn-EDTA at flowering and foliar spray of 0.5% chelated Zn-EDTA at active tillering?+?flowering?+?grain filling, respectively. Correlation analysis showed positive correlation between Zn uptake and grain yield.     

Lipid-based Fe- and Zn- nanoformulation is more effective in alleviating Fe- and Zn- deficiency in maize

Improving uptake, translocation, and utilization of foliar applied Fe and Zn is essential for increasing biomass and grain yield under deficient conditions. We compared the effect of foliar applied lipid-based Pheroid Fe- or Zn- nanoformulation, chelate and sulfate forms on biomass, nutrient uptake and mobilization in maize grown under Fe and Zn deficiency scenarios in hydroponic systems and field trials. Foliar spray of Fe-Pheroid nanoformulation resulted in complete re-greening. Partial and no re-greening of mature and young leaves, respectively, were observed under FeSO₄ and Fe-HEDTA treatments. Foliar spray of Zn-Pheroid nanoformulation increased the Zn concentration of young leaves. In field trials, foliar spray of Fe- or Zn- chelate did not improve leaf Fe and Zn concentration or grain yield. Fe- and Zn-Pheroid nanoformulation improved the mobility of Fe and Zn within the plant. Field trials indicated that non-lipid-based formulation was not effective in amelioration of Fe- and Zn deficiency.     

锌与磷肥不同混合方式对玉米产量及磷、锌利用的影响

  【目的】  研究锌与磷肥以不同混合方式施用对玉米干物质量、籽粒产量及磷、锌利用率的影响,以期为锌与磷肥科学配伍及新型含锌磷肥的研制提供理论依据。  【方法】  将七水硫酸锌(Zn)按0.5%和5%(W/W)的添加量与磷肥(P)分别进行物理混合(P+Zn)和反应混合(PZn),制备含锌磷肥试验产品:P+Zn0.5、P+Zn5、PZn0.5和PZn5。采用玉米土柱栽培试验,设置8个处理,包括分别施用以上4种含锌磷肥(P+Zn0.5、P+Zn5、PZn0.5和PZn5)、普通磷肥(P)和硫酸锌(Zn0.5、Zn5),以不施肥为对照(CK)。所有肥料均作为基肥一次性施入土柱 0—30 cm 土层。玉米成熟后,收获、考种,测定玉米植株不同部位(茎秆、叶片、苞叶、穗轴、籽粒)干物质量、磷和锌含量,以及采集 0—30、30—60、60—90 cm 土层土壤速效磷和有效锌含量。  【结果】  1)与普通磷肥相比,锌与磷肥混合处理玉米地上部干物质量和籽粒产量分别平均提高了15.18%、7.70%,反应混合(PZn)效果优于物理混合(P+Zn),PZn主要通过增加穗粒数实现增产,锌肥低添加量PZn0.5增产效果显著优于高添加量PZn5。2)与普通磷肥相比,PZn0.5处理玉米地上部和籽粒磷吸收量分别提高了8.40% 和 16.67%,磷肥表观利用率提高了5.03个百分点,磷肥农学效率和偏生产力分别提高了41.91%和11.64%;与PZn5相比,PZn0.5的磷肥表观利用率提高4.78个百分点,磷肥农学效率和偏生产力分别提高了14.57%和3.58% (P<0.05)。3)与普通磷肥相比,施用PZn肥玉米籽粒锌累积量平均提高了21.90% (P<0.05);与P+Zn肥相比,施用PZn肥玉米地上部锌累积量平均提高了25.70%,锌肥利用率平均提高了7.83个百分点(P< 0.05)。  【结论】  锌与磷肥混合后施用能够增加玉米干物质量和籽粒产量,其中反应混合方式在提高玉米对磷、锌的吸收量和磷、锌肥利用率以及提高土壤速效磷、有效锌含量等方面的效果优于物理混合,且以硫酸锌0.5%添加量与磷肥反应混合效果最佳。