首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Abstract

Lucerne (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires boron (B) addition as the soils are naturally B deficient. Field experiments with four B-application rates (0, 1, 3, and 9 kg ha?1 B) were conducted in 2005 and 2006 to determine the optimum economic B rate (OEBR), critical soil test and tissue B values for dry matter (DM) production for lucerne grown on B-deficient calcareous aridisols in eastern Turkey. Boron application increased yield at each site in both years of production. The OEBR and critical soil and tissue B content were not impacted by location. Averaged over the two years and three locations, the OEBR was 6.8 kg B ha?1 with an average DM yield of 12.0 Mg ha?1. The average soil B content at the OEBR was 0.89 mg kg?1 while leaf and shoot tissue B content amounted to 51.8 and 35.5 mg kg?1, respectively. Boron application decreased tissue calcium (Ca), zinc (Zn), and copper (Cu), and increased tissue nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe), and manganese (Mn). Tissue and soil B increased without impacting yield at B levels up to 9 kg ha?1. We conclude that 7 kg ha?1 B is sufficient to elevate soil test B levels from 0.11 to 0.89 mg kg?1 and overcome B deficiency at each of the sites in the study. Similar studies with different soils and initial soil test B levels are needed to conclude if these critical soil and tissue values can be applied across the region.  相似文献   

2.
Phytoremediation is an attractive, economic alternative to soil removal and burial methods to remediate contaminated soil. However, it is also a slow process. The effect of humic acid in enhancing B and Pb phytoextraction from contaminated soils was studied (pot experiment) using transplanted vetiver grass (Vetiveria zizanioides (L.) Nash). Boron was applied at 0, 45, 90 and 180 kg B ha?1 soil (as H3BO3) in 16 replicates. Of the 64 pots, four pots each were treated with 0, 100, 200 and 400 kg ha?1 humic acid (HA) solution. In a separate experiment, Pb was applied (as Pb(NO3)2) at 0, 45, 90 and 180 kg Pb ha?1 prior to addition of HA solutions at levels identical to the B experiment. Experiments were conducted using a randomized complete block design with four replicates. Vetiver grass was harvested 90 days after planting. Lead addition beyond 45 kg Pb ha?1 decreased Pb uptake mostly due to a yield decline. Humic acid application increased Pb availability in soil and enhanced Pb uptake while maintaining or enhancing yield. An application of 200 kg HA ha?1 was optimal for maintaining yield at elevated Pb levels. Boron application did not impact yield but greatly increased B content of roots and shoot. Boron uptake was greatest upon addition of 400 kg HA ha?1. We conclude that HA addition to vetiver grass can be an effective way to enhance phytoremediation of B and Pb but optimum rates differ depending on soil B and Pb contamination levels.  相似文献   

3.
Boron (B) deficiency is potentially an important nutrient constraint in calcareous soils. We determined B deficiency incidence and spatial distribution in rainfed wheat (Triticum aestivum L.) in 1.82 Mha Pothohar plateau in Pakistan, its relationship with soil types, crop responses to B, and internal B requirement and B fertilizer use efficiency of wheat. Plant and soil analyses indicated deficiency in 64% of the 61 sampled fields; geostatistics-aided contour maps delineated B deficient areas. In rainfed field experiments, B use increased wheat yields up to 11%. Fertilizer requirement was 1.2 kg B ha?1; critical B concentration (mg kg?1) ranges were: young whole shoots, 4–6; flag leaves, 5–7. Boron uptake by wheat was 0.14–0.58% of applied dosage, leaving substantial residual impact. Highly cost-effective B use or B-efficient genotype adoption can enhance wheat productivity and grower-income. Such effective nutrient assessment and management approaches can be beneficially adopted elsewhere as well.  相似文献   

4.
Micronutrient and amino acid (AA) foliar fertilization has generally been sprayed onto plants to increase the crop yield. The experiment had the aim of evaluating the foliar boron (B) and AA application on grain yield (GY), physiological characteristics, nutritional status, and yield components in wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merrill] intercropping in a non-tillage system (NTS). The experiment was set up as a randomized block design with eight treatments and four replicates. The treatments had the following boron (B) rates: [0, 1, 2, 4, and 8 kg ha?1, source: boric acid (H3BO3)] + AAs (2 L ha?1) applied by foliar spraying and the additional treatments [(Control - without B and AAs), 2 kg ha?1 B, 2 L ha?1 AAs and 2 kg ha?1 B + 1 L ha?1 AAs] applied at the end of the elongation and spike beginning of wheat plants and development growth stage (V5) of soybean for two growing seasons. Boron and AAs had no influence on the physiological and yield components and had no increases in the foliar and grain B content in wheat and soybean. No matter the dose, the foliar B + AAs (2 L ha?1) application did not increase the GY in wheat-soybean under a rotational NTS in loamy soil with suitable available B.  相似文献   

5.
Boron (B) deficiency hampers cotton (Gossypium hirsutum L.) growth and productivity globally, especially in calcareous soils. The crop is known as a heavy feeder of B; however, its reported plant analysis diagnostic norms for B-deficiency diagnosis vary drastically. In a 2-year field experiment on a B-deficient [hydrochloric acid (HCl)–extractable 0.47 mg B kg?1], calcareous, Typic Haplocambid, we studied the impact of soil-applied B on cotton (cv. CIM-473) growth, productivity, plant tissue B concentration, and seed oil composition. Boron was applied at 0.0, 1.0, 1.5, 2.0, 2.5, and 3.0 kg B ha?1, as borax (Na2B4O7·10H2O), in a randomized complete block design with four replications, along with recommended rates of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). Boron use improved crop growth, decreased fruit shedding, and increased boll weight, leading to seed cotton yield increases up to 14.7% (P < 0.05). Improved B nutrition of plants also enhanced seed oil content (P < 0.05) and increased seed protein content (P < 0.05). Fiber quality was not affected. Fertilizer B use was highly cost-effective, with a value–cost ratio of 12.3:1 at 1 kg B ha?1. Fertilizer B requirement for near-maximum (95% of maximum) seed cotton yield was 1.1 kg B ha?1 and HCl-extractable soil B requirement for was 0.52 kg ha?1. Leaf tissue B requirement varied with leaf age as well as with plant age. In 30-day plants (i.e., at squaring), B-deficiency diagnosis critical level was 45.0 mg kg?1 in recently matured leaves and 38.0 mg kg?1 in youngest open leaves; at 60 days old (i.e., at flowering), critical concentration was 55.0 mg kg?1 in mature leaves and 43.0 mg kg?1 in youngest leaves. With advancement in plant age critical B concentration decreased in both leaf tissues; that is, in 90-day-old plants (i.e., at boll formation) it was 43.0 mg kg?1 in mature leaves and 35.0 mg kg?1 in the youngest leaves. As critical concentration range was narrower in youngest leaves (i.e., 35–43 mg kg?1) compared with mature leaves (i.e., 43–55 mg kg?1), B concentration in youngest leaves is considered a better indicator for deficiency diagnosis.  相似文献   

6.
Yield‐response correlations with old and improved soil extraction methods for boron (B) are needed. Russet Burbank potato (Solanum tuberosum L.) was grown with two, four, and six B treatments applied in 2004, 2005, and 2006, respectively. Zero and 1.1, 2.2, or 3.4 kg B ha?1 soil and 0.22 or 0.28 kg B ha?1 foliar treatments were applied. Boron fertilization did not significantly increase tuber yield or quality despite initially low hot‐water‐extractable B (0.34–0.50 mg kg?1), although postseason B for unfertilized treatments increased (0.51–0.57 mg kg?1). Soil‐applied B generally reflected B application relative to the untreated control and the low foliar rates in all three years for the four soil extractions utilized [hot water, pressurized hot water, diethylenetriaminepentaacetic acid (DTPA)–sorbitol, and Mehlich III]. Boron content of potato petiole did reflect application of B in 2 years, but tuber and peel tissues did not consistently reflect application of B.  相似文献   

7.
ABSTRACT

Modern agriculture over the years has resulted in depletion of boron (B) from soil which has been emerged as a serious obstacle for sustainable agriculture. We studied the availability of B in soil and cauliflower (Brassica oleracea var. botrytis L.) productivity under different levels of B fertilization. A field experiment was conducted during 2013–2014 and 2014–2015, at experimental farm of Himachal Pradesh Agricultural University, Palampur on silt-clay loam soil (acid Alfisol) under mid hill wet temperate condition. Different levels of B for the study included 0, 0.75, 1.5, 2.5, 5, 10, 20 and 30 kg B ha?1 along with recommended dose (RD) of NPK and farmyard manure (FYM, 20 t ha?1). The application of B influenced biological yield significantly up to 5 kg ha?1. Highest curd yield in 2013–2014 (11.03 t ha?1) and 2014–2015 (12.93 t ha?1) was recorded in 1.5 and 0.75 kg ha?1 B along with NPK + FYM, respectively. At higher rates of boron i.e. 10, 20 and 30 kg ha?1, due to toxic effects, a reduction in curd yield was recorded in both years. Maximum mean uptake of N, P and K by leaves and curd was recorded with the application of boron at 1.5 kg ha?1, whereas mean B uptake was highest when boron was applied at 2.5 kg ha?1. The highest mean value (1.79 mg kg?1) of soil available boron was recorded with 30 kg B ha?1. Application of boron at 2.4 kg ha?1 was worked out as optimum dose for cauliflower.  相似文献   

8.
Boron (B) deficiency frequently occurs on soils that are low in organic carbon (C) (<1.0% organic C), pH (soil pHCa <5.0), and clay content (<5% clay). Acid sands with these soil properties are common in south-western Australia (SWA). Moreover, hot calcium chloride (CaCl2) extractable B levels are commonly marginal in the acid sands of SWA. This study examined the effects of soluble and slow release soil-applied B fertilizer and foliar B sprays on crops most likely to respond to B fertilizer on these soils, canola (oil-seed rape, Brassica napus L.) and lupin (Lupinus angustifolius L.).

At 25 sites over three years, canola was grown with (0.34 kg ha-1) or without B applied as borax [sodium tetraborate decahydrate (Na2B4O7·10H2O) 11% B], and this was followed by nine experiments with B rates [0, 0.55, 1.1 kg ha?1, applied as borax or calcium borate (ulexite, NaCaB5O6(OH)6·5(H2O), 13% B] and foliar sprays (0.1% solution of solubor, 23% B) in 2000–2001. A further five sites of B rates and sources experiments were carried out with lupin in 2000–2001. Finally, foliar B sprays (5% B w/v as a phenolic complex) at flowering were tested on seven sites in farmers’ canola crops for seed yield increases. No seed yield increases to soil-applied B were found while foliar B application at flowering increased canola seed yield in only one season across seven locations. By contrast, borax fertilizer drilled with the seed at sowing decreased canola seed yield in nine of 34-farm sites, and decreased lupin yield in two of five trials. Toxicity from drilled boron fertilizer decreased yield could be explained by decreases in plant density (by 22–40%) to values lower than required for optimum seed yield. Seedling emergence was decreased by borax applied at sowing but less so by calcium borate. Foliar B spray application never reduced seed yield due to toxicity effects.

Boron fertilizer drilled with the seed increased the B concentration in plant dry matter at early to mid-flowering. Boron application decreased the oil concentration of grain of canola at four sites. The oil yield of canola was significantly decreased at seven sites.

Notwithstanding the marginal B levels on acid sands of the SWA region, care needs to be taken on use of borax fertilizer as toxicity was induced in canola and lupin; with 0.34 to 1 kg B ha?1(3-10 kg borax ha?1) at sowing depressing seed yield, mostly by decreasing plant density. Rather than making general recommendation for B fertilizer application based on 0.01M CaCl2 soil extractable B, soil and plant analysis should be used to diagnose B deficiency and B fertilizer use limited to calcium borate or foliar borax rather than soil-applied borax on low B sands.  相似文献   

9.
Boron (B) is known to play important roles in the structures of cell walls and membranes and in the integrity and functions of membranes in plants. Under the conditions in the central Amazon region, there are few studies about this nutrient. In Brazilian soils, the hot-water B extraction method has been extensively used for evaluation of soil B status. However, difficulties with this method result in poor accuracy and precision of extraction of available B in soil. The objective of this study was to evaluate the yield, foliar concentration, and efficiency of B extracting solutions and the effect of B fertilization on B uptake in banana (Musa spp.) leaves and fruits, subgroup Cavendish (AAA), cultivated in a Xanthic Ferralsol (dystrophic Yellow Latosol) located in Amazonas State, Brazil. The experimental design was a completely randomized split plot, with four B rates (0, 4, 8, and 12 kg ha?1), two harvest cycles (subtreatments), and four replicates. Available B was determined with seven extractant solutions: Mehlich 1, Mehlich 3, hot water, hydrochloric acid (HCl) 0.05 mol L?1, HCl 0.1 mol L?1, HCl 5.0 mol L?1, and potassium chloride (KCl 1.0 mol L?1). The application of B fertilizer increased the yield and B concentration in leaves and fruits. Hot water and KCl 1.0 mol L?1 were the most efficient extracting solutions for the determination of available B in soil. The application of 3.4 kg B ha?1 in the first cycle and 1.3 kg B ha?1 in the second cycle guarantees an adequate nutritional status in banana plants.  相似文献   

10.
Abstract

Good and balanced citrus nutrition is important for high fruit yields and improved tree performance. A study was conducted for 2?years to investigate the effect of soil application of boron (B) on leaf nutrient content, canopy size, and root length density (RLD). The study was conducted on 10-year-old Candidatus Liberibacter asiaticus (CLas)-infected Vernia sweet orange on Rough Lemon rootstock in a commercial grove east of St. Cloud, FL planted at 375 trees ha?1 on a traditional soluble dry nutrition and spray programs. Treatments were supplied with various ground-applied controlled-release fertilizer treatments containing B. Boron was applied at 0×, 2×, and 4× current University of Florida recommendation where 1×?=?1.12?kg ha?1. Data collected included leaf B nutrient content, soil B concentration, trunk diameters, canopy volumes, soil electrical conductivity, and soil pH. The 0×, 2×, and 4× application rates corresponded with leaf nutrient contents ranging from 56?mg kg?1 and 88?mg kg?1 in March 2017, 162?mg kg?1 and 288?mg kg?1 in September 2017, and 122?mg kg?1 and 320?mg kg?1 in May 2018. Temporary, RLD decreased with time from March to September 2017 by 13, 30, and 37% at the 0, 2.24, and 4.48?kg B ha?1 and increased by 309, 258, and 306% at the 0, 2.24, and 4.48?kg B ha?1, respectively, from September 2017 to May 2018. No consistent pattern was established between soil B application with canopy size.  相似文献   

11.
Boron (B) application is an important strategy in highly productive systems, since this micronutrient is involved in amide syntheses, which is related to the grain yield. In this way, the aim of this work was to evaluate the B fertilization effect in nutrition and production of common beans. The experiment was carried out under greenhouse condition, in an entirely randomized design, with five B doses (0, 1, 2, 4, and 6 kg ha?1) and four repetitions. The relative chlorophyll index, dry mass production, level and accumulation of B were measured. Boron levels in leaves of common beans are linearly enhanced after application of increasing B doses. When B level in soil is low (<0.5 mg kg?1), boron doses lower than 4.9 kg ha?1 increase dry mass production, with the highest production observed at a dose of 4.8 kg ha?1, promoting a 56% in dry mass production compared with control.  相似文献   

12.
Boron (B) deficiency is a common factor in light-textured soils causing poor pod filling and yield in large seeded peanut. Field trials were conducted in soils having 0.20–0.45 mg kg?1 available B to find out the effectiveness of commercial-grade B sources in large seeded peanuts. B application induced early flowering, increased pods, yield and yield attributes, shelling and 100-seed weight. Soil application of 2.0 kg B ha?1 as commercial-grade Agricol, Solubor and Borosol increased these parameters to a similar degree as obtained by borax, but were superior over their foliar applications. Similarly, the responses of foliar applications of 1.0 kg B ha?1 as Chemiebor, Solubor and Borosol were more effective in humid areas. However, foliar applications led to scorching of peanut leaves during dry weather. Thus, soil application of 2.0 kg B ha?1 is essential to enhance productivity and pod filling in large seeded peanut.  相似文献   

13.
Limited information is available on the effect of slow-release boron (B) fertilizer on Pinus radiata growth and physiological properties and soil microbiological activities. A 7-month-long pot experiment was carried out under glasshouse conditions to investigate the response of Pinus radiata to different rates (0.0222, 0.0446, 0.089, and 0.178 mg B g?1 soil), equivalent to 0, 4, 8 16, and 32 kg B ha?1 of ulexite, a slow-release B fertilizer. Hot 0.02 M calcium chloride (CaCl2)–extractable soil B, soil dehydrogenase activity, plant B concentration, growth, and photosynthesis were measured at the time of harvest. The B concentrations in the soil and plant organs (needles, stem, and roots) significantly increased with increasing rates of B fertilizer. The optimum B fertilizer rates of 4–8 kg B ha?1 produced the greatest plant growth and net photosynthetic rate. However, the B rates of 16 and 32 kg B ha?1 significantly reduced net photosynthetic rate, and the rate of 32 kg B ha?1 significantly reduced stem diameter growth when compared to the optimum B rates. Soil dehydrogenase activity, an indicator of soil microbiological activities, was significantly reduced by B application at the rates of 16 and 32 kg ha?1. This study confirms the narrow range between B deficiency and toxicity in a tree crop and stresses the need for selection of the optimum rate of B fertilizer application.  相似文献   

14.
Field experiments were conducted to study the response of cotton genotypes (G. arboreum Bt cv. RCH 650 BGII; non-Bt cv. F 2228; G. herbaceum cv. FDK 124) and wheat and triticale genotypes (T. aestivum cv. PBW 622; T. durum cv. PDW 314; triticale cv. TL 2908) to direct and residual B application (0, 0.5, 1.0, and 2.0 kg B ha?1 as borax) using a Typic Ustrochrept, neutral, noncalcareous, loamy sand and B-deficient soil. A significant response of 218 and 231 kg ha?1 in seed cotton yield was recorded with an application of 1.0 kg B ha?1 to cotton and 2.0 kg B ha?1 to wheat. A significant response of 152 kg ha?1 grain yield of wheat was observed with the application of 0.5 kg B ha?1 to wheat, while no residual effect of B was observed when B was applied to cotton. On the basis of agronomic and B uptake efficiency, genotypes of cotton (RCH 650 BG II > FDK 124 > F 2228) and wheat (PDW 314> TL 2908> PBW 621) responded differentially to B application, thus indicating that yield of Bt cotton and durum wheat will be reduced more than the other cultivars under B deficiency.  相似文献   

15.
Understanding the effect of boron (B) on plant physiology will help to refine the diagnosis of B deficiency and improvement in B fertilizer recommendations for cotton (Gossypium hirsutum L.) growing areas. This study shows the testing of hypotheses “that application of B-fertilizer improves net photosynthetic rate (PN) and water use efficiency (WUE) for cotton plant on a B-deficient soil [< 0.50 mg B kg?1 hydrochloric acid (HCl)-extractable] in an arid environment”. Thus, a permanent layout [two-year field experiment (2004 and 2005)] was conducted to study the impact of B fertilizer at 0, 1.0, 1.5, 2.0, 2.5, and 3.0 kg ha?1 on gas exchange and electrolyte leakage (EL) characteristics of cotton crop (cv. ‘CIM-473’). The soil at experimental site was alkaline (pH 8.1), calcareous [calcium carbonate (CaCO3 5.6%)], and silt loam (Typic Haplocambid). Boron use decreased EL of plant membrane (P ≤ 0.05), and increased PN, transpiration rate (E) and stomatal conductance (gs), while intercellular concentration of carbon dioxide (CO2; Ci) significantly decreased (P ≤ 0.05) during both experimental years. There was a positive, but non-significant effect of B concentration on chlorophyll content in plant leaves. Application of 3.0 kg B ha?1 improved WUE up to 9.7% [4.62 μmol (CO2) mmol?1 water (H2O)] compared to control plants (4.21 [μmol (CO2) mmol?1 (H2O)]. Principal component analysis (PCA) of data indicates positive correlations between leaf B concentration and PN, E, gs, and WUE, while a negative relationship existed between leaf B concentration and intercellular CO2 (Ci). This study showed that addition of B fertilizer in the B-deficient calcareous soil proved beneficial for growth and development for cotton crop by enhancing its WUE and gas exchange characteristics.  相似文献   

16.
In this study, 24 years (1990–2013) of data from a long-term experiment, in Stillwater, Oklahoma (OK), were used to determine the effect of beef manure on soil test phosphorus (STP), soil organic carbon (SOC), and winter wheat (Triticum aestivum L.) yield. Beef manure was applied every 4 years at a rate of 269 kg nitrogen (N) ha?1, while inorganic fertilizers were applied annually at 67 kg N ha?1, 14.6 kg phosphorus (P) ha?1, and 27.8 kg potassium (K) ha?1 for N, P, and K, respectively. Averaged across years, application of beef manure, and inorganic P maintained STP above 38 mg kg?1 of Mehlich-3 extractable P, a level that is far beyond crop requirements. A more rapid decline in SOC was observed in the check plot compared to the manure-treated plot. This study shows that the application of animal manure is a viable option to maintaining SOC levels, while also optimizing grain yield.  相似文献   

17.
Field studies were conducted to assess boron (B) requirement, critical concentrations in diagnostic parts based on yield response curves and genotypic variation by growing three peanut (Arachis hypogaea L.) cultivars (‘Golden’, ‘BARD-479’, ‘BARI-2000’) on two B-deficient calcareous soils. Boron application significantly increased pod yield of all the cultivars over control. Maximum pod yield increases were: ‘Golden’, 16?23%; ‘BARD-479’, 21?27%; and ‘BARI-2000’, 25?31%. The cultivars varied in B efficiency and cv. ‘Golden’ was the most B efficient (81?86%) while cv. ‘BARI-2000’ was the least efficient (76?80%). Boron requirements for near-maximum (95%) dry pod yield were 0.65 kg ha?1 for ‘Golden’, 0.75 kg ha?1 for BARD-479 and 0.80 kg ha?1 for BARI-2000. Critical B concentrations in shoots and seeds were: ‘Golden’, 33 mg kg?1 and 26 mg kg?1; ‘BARD-479’, 38 mg kg?1 and 31 mg kg?1; and ‘BARI-2000’, 42 mg kg?1 and 33 mg kg?1.  相似文献   

18.
Balanced plant nutrition is essential to achieve high yields of canola (Brassica napus L.) and get the best economic return from applied fertilizers. A field study was conducted at nine site‐years across eastern Canada to investigate the effects of nitrogen (N), sulfur (S) and boron (B) fertilization on canola nutrient uptake, nutrient balance, and their relationship to canola yields. The factorial experiment consisted of four N rates of 0 (N0), 50 (N50), 100 (N100), and 150 (N150) kg ha?1, two S rates of 0 (S0) and 20 (S20) kg ha?1, and three B treatments of 0 (B0), 2 kg ha?1 at preplant (B2.0P), and 0.5 kg B ha?1 foliar‐applied at early flowering stage (B0.5F). Each site‐year used the same experimental design and assigned treatments in a randomized complete block design with four replications. Fertilizer S application greatly improved seed yields at six out of nine site‐years, and the highest N use efficiency was in the N150+S20 treatment. Sulfur application generally increased seed S concentration, seed S removal, and plant total S uptake, while B fertilization mainly elevated straw B concentration and content, with minimal effect on seed yields. At the early flowering stage, plant tissue S ranged from 2.2 to 6.6 mg S g?1, but the N : S ratio was over or close to the critical value of 12 in the N150+S0 combination at five site‐years. On average across nine site‐years, canola reached a plateau yield of 3580 kg ha?1 when plants contained 197 kg N ha?1, 33 kg S ha?1 and 200 g B ha?1, with a seed B content of 60 g B ha?1. The critical N, S, and B values identified in this work and their potential for a posteriori nutrient diagnosis of canola should be useful to validate fertilizer requirements for canola production in eastern Canada.  相似文献   

19.
Boron (B) is an essential microelement, which is necessary for reproductive organs including pollen tube formation in wheat (Triticum aestivum L.), and flowering and boll formation in cotton (Gossypium hirsutum L.) The study was associated with wheat-cotton rotation in 80 farm fields, belonging to different soil series, in four districts of cotton belt of Punjab, Pakistan to assess concentrations of extractable B in soils [0.05 M hydrochloric acid (HCl) extractable B], and added fertilizer B and their relationship to some soil physico-chemical properties [pH, organic matter (OM), calcium carbonate (CaCO3) and clay content], yields and total B concentrations in wheat and cotton plants. All soils had alkaline pH (7.45 to 8.55), high CaCO3 content (2.14 to 8.65%), less than 1.0% OM (0.33 to 0.99%), low plant available-P (Olsen P less than 8 mg kg?1 soil) and medium ammonium acetate extractable potassium (K) (< 200 mg K kg?1 soil). Of the 80 soil samples, 65 samples (81%) were low in available B (<0.45 mg B kg?1, ranging from 0.11 to 0.43 mg B kg?1) Of the corresponding 80 plant samples, leaves B concentrations were below critical levels (<10 mg B kg?1 for wheat; <30 mg B kg?1 for cotton) for all the tested samples for wheat and cotton. The regression analysis between plant total B concentrations and soil extractable B concentrations showed strong linear positive relationships for both wheat (R2 = 0.509***, significant at P <0.001) and cotton (R2 = 0.525***, significant at P <0.001). Further regression analysis between extractable soil B and wheat grain yield as well as between wheat leaves total B and wheat grain yield also depicted strong linear relationships (R2 = 0.76 and 0.42, respectively). Boron fertilizer demonstration plots laid out at farmers’ fields low in extractable B, in each district not only enhanced grain yields of wheat crop but also contributed a significant increase towards seed cotton yield of succeeding cotton crop through residual B effect. In conclusion, the findings suggest that many soils in the cotton belt of Punjab may be low in extractable B for wheat and cotton, especially when these crops are grown on low OM soils with high CaCO3 content.  相似文献   

20.
A long‐term field experiment on a Haplic Phaeozem, established 1949 with four levels of potassium (K) supply (5, 69, 133, and 261 kg K ha?1), was analyzed for the interaction between K supply and yield loss of five crop species by water shortage. The crop species were cultivated simultaneously side‐by‐side in the following rotation: potato (Solanum tuberosum L.), silage maize (Zea mays L.), spring wheat (Triticum aestivum L.), beet (Beta vulgaris L.), and spring barley (Hordeum vulgare L.). The treatment with 133 kg K ha?1 supply had a nearly balanced K budget. In the treatments with lower supply, the soil delivered K from its mineral constituents. On the low‐K plots (especially on those with only 5 kg K ha?1), crops suffered yield depressions of nearly all main harvest products (cereal grains, potato tubers, beet storage roots, silage maize) and by‐products (straw, beet leaves) by up to 40.7% of dry matter. Only wheat grains were an exception. Potassium concentrations in the harvested plant parts decreased nearly in parallel to the reduction of their dry matter yields, with the exception of cereal grains, which kept stable concentrations even in the treatment with only 5 kg K ha?1. A comparison of four year‐pairs with differing levels of precipitation in yield‐relevant periods showed an average water shortage‐induced depression of dry matter yields by 19.7% in the main harvest products. The severity of this yield depression was not mitigated by elevated K supply, with the exception of beet leaves, where the dry matter production was stabilized by high K supply. In this crop, the reduction of storage‐root yield was associated with a decrease in harvest index and was therefore obviously caused by an inhibition of assimilate translocation from the leaves into these organs, in contrast to cereals, where water shortage primarily affected dry matter production in vegetative organs. It is concluded that the physiological causes of yield reduction by drought stress and the possibility of its amelioration by K supply differ between plant species and organs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号