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1.
Abstract

Zinc (Zn) deficiency is a widespread micronutrient disorder in crops grown in calcareous soils; therefore, we conducted a nutrient indexing of farmer‐grown rainfed wheat (Triticum aestivum, cv. Pak‐81) in 1.82 Mha Potohar plateau of Pakistan by sampling up to 30 cm tall whole shoots and associated soils. The crop was Zn deficient in more than 80% of the sampled fields, and a good agreement existed between plant Zn concentration and surface soil AB‐DTPA Zn content (r=0.52; p≤0.01). Contour maps of the sampled areas, prepared by geostatistical analysis techniques and computer graphics, delineated areas of Zn deficiency and, thus, would help focus future research and development. In two field experiments on rainfed wheat grown in alkaline Zn‐deficient Typic Haplustalfs (AB‐DTPA Zn, 0.49–0.52 mg kg?1), soil‐applied Zn increased grain yield up to 12% over control. Fertilizer requirement for near‐maximum wheat grain yield was 2.0 kg Zn ha?1, with a VCR of 4∶1. Zinc content in mature grain was a good indicator of soil Zn availability status, and plant tissue critical Zn concentration ranges appear to be 16–20 mg kg?1 in young whole shoots, 12–16 mg kg?1 in flag leaves, and 20–24 mg Zn kg?1 in mature grains.  相似文献   

2.
Background : Nepal's traditional rice–wheat rotation systems are subject to continuing changes. Changing consumer demand currently drives a replacement of wheat by high‐value vegetables during the dry season, while emerging water shortages lead to a substitution of rice by maize in the wet season. Hence, associated changes in soil aeration status and shifting conditions of soil nutrient supply to match crop nutrient demand are expected to increase the requirements for the principle limiting micro‐nutrients such as boron (B) and zinc (Zn). Aim: Our aim was to investigate the changes in B and Zn availability as well as crop yields and nutrient uptake after system shifts from rice to maize and from wheat to vegetables. Method : We analyzed the B and Zn availability in rice‐ and maize‐based systems as well as crop yields and the nutrient uptake by wheat, cauliflower, and tomato during the dry season in Nepal. Plants were grown at two field sites (midhills vs. lowland) and under greenhouse conditions using soils from the field sites. Results : A change from irrigated rice to maize reduced soil C and N contents with resulting decreases in dry season crop yields. Low soil Zn after rice cultivation led to shortage in Zn uptake by vegetables in both greenhouse and field experiments. The shift from wheat to vegetables increased the demand for B and to a lesser extent for Zn, and consequently vegetables showed visual symptoms of B deficiency. Boron concentrations in dry biomass were below the critical limits with < 10 mg B kg?1 in wheat, < 21 mg B kg?1 in cauliflower, and < 23 mg B kg?1 in tomato. Conclusions: Soils in larger parts of Nepal are low in available B and that the ongoing system shifts increase in the demand for B and Zn in the currently emerging and more diversified production systems.  相似文献   

3.
《Journal of plant nutrition》2013,36(12):2591-2602
ABSTRACT

No boron (B) deficiencies have been reported for rice (Oryza sativa L.) grown in the United States and, when occurring elsewhere, reports often lack details of deficiency symptoms and leaf-B critical values. An experiment was conducted to determine the effect of B and lime on yield, pollen viability, and to determine diagnostic symptoms of B deficiency in rice. Rice cv. “Bengal” was grown in the greenhouse on a soil acquired from a rice farm from SW Louisiana in the United States, a Caddo silt loam (Caddo sl) (Typic Glossaqualf, fine-silty, siliceous, thermic), treated with 0.44?mg?B?kg?1 (+B) or no B (?B). Split plots were limed at rates of (i) none; (ii) 224?mg?kg?1 CaO+40.3?mg?kg?1 MgO; and (iii) 673?mg?kg?1 CaO+121?mg?kg?1 MgO. Rice was also grown in ?B and +B potting media and in ?B sand culture using nutrient solution identical to that used in other studies of ours. Rough-rice yields from the +B Caddo sl treatment was 11% higher than from the ?B treatment (29.3 vs. 26.3?g?pot?1; P=0.02). The yield increase was likely due to fewer damaged pollen (8%) found from the +B than the ?B treatment (17%; P=0.014). Leaf-B at tillering was 11.3?mg?kg?1 for the B-treated rice and 7.1?mg?kg?1 from the ?B treatment. Liming did not significantly affect leaf B or yields. Boron deficiency symptoms were found only in the ?B sand-culture where yields were 1.1?g?pot?1, 96% less than that from the +B Caddo sl. Symptoms were like those found in our earlier hydroponic studies with twisted and whitish leaf tips starting at tillering and 1-cm white bands across the width of leaves. Maturity was delayed about four weeks. Boron deficiency from the Caddo sl and sand treatments occurred with leaf B≤7?mg?kg?1 and with a Caddo sl soil B of 0.18?mg?hws (hot-water soluble) B?kg?1. Given that no B deficiency symptoms were found in rice experiencing moderate yield loss grown on the rice soil, one must rely on soil and plant analyses to help detect likely candidates for moderate B deficiency.  相似文献   

4.
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   

5.
Abstract

Boron (B) deficiency in crops is a major micronutrient disorder particularly in alkaline‐calcareous soils. A nutrient indexing of rainfed sorghum [Sorghum bicolor (L.) Merr; cv. Potohar 4–8] in the Potohar plateau of Pakistan revealed B deficiency in 50% of the 140 sampled fields in Jehlum district and 115 fields in Chakwal district. Hot water extractable (HWE) B in the associated soils, however, indicated more widespread B deficiency. The 255 sampled fields represented 21 soil series: 100 belonging to Alfisols, 63 to Entisols, 50 to Inceptisols, and 42 to Aridisols. Boron fertility varied in various soil types; the minimum HWE B (0.25 mg/kg) was noted in Calci Ustochrepts and the maximum (0.69 mg/kg) in Fleventic Ustochrepts. Boron fertilization of an alkaline calcareous Typic Ustorthents (HWE B, 0.11 mg/kg) increased grain yield up to 32% in improved sorghum (cv. PARC‐SS‐1) and 29% in local sorghum (cv. Potohar 4–8) over the respective control yields. Fertilizer requirements for near‐maximum (95%) grain yield was 1.2 mg B/kg for the improved and 0.6 mg B/kg for local cultivar; higher fertilizer requirement of improved sorghum may be attributed to its greater biomass production. Critical plant tissue B concentration in improved sorghum was 17 mg/kg in whole shoots and 25 mg/kg in most recently matured leaves. Contrary to its lesser fertilizer requirement, internal B requirement of local sorghum was greater, i.e., 18 mg/kg in whole shoots and 31 mg/kg in leaves. The three soil tests for B, hot water, hydrochloric acid (HC1), and mannitol were almost equally effective in evaluating soil B fertility. Soil test critical B levels (mg/ kg) for improved sorghum were: hot water, 0.48; HC1, 0.43; and mannitol, 0.37. Contrary to its internal B requirements, soil test critical B levels (mg/ kg) were slightly lower for local sorghum, i.e., hot water, 0.45; HC1, 0.40; and mannitol, 0.36. Thus, local sorghum appeared more efficient in utilizing soil B. As soil test critical levels as well as fertilizer requirement were greater for improved sorghum, a much widespread B deficiency is expected in this cultivar if grown on alkaline calcareous soils of the Potohar plateau.  相似文献   

6.
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   

7.
In many parts of the world, boron (B) levels are insufficient for potential production. Boron deficiency is also widespread in the Anatolia region of Turkey. Boron deficiency could impact production and quality of tomatoes (Lycopersicon esculentum L.), pepper (Capsicum annum L.), and cucumber (Cucumis sativus L.). A two-year greenhouse experiment was conducted to study yield and quality response of three vegetables to B addition (0, 1, 2, 3, and 4 kg B ha?1). The optimum economic B rates (OEBR) were 2.3, 2.6, 2.4 kg B ha?1, resulting in soil B concentrations of 0.33, 0.34 and 0.42 mg kg?1. Independent of plant species, B application decreased tissue nitrogen (N), calcium (Ca), and magnesium (Mg) but increased tissue phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations. We conclude that a B addition of 2.5 kg ha?1 is sufficient to elevate soil B levels to nondeficient levels. Similar studies with different soils and initial soil-test B levels are needed to conclude if these critical soil test values and OEBR can be applied across the region.  相似文献   

8.
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.  相似文献   

9.
Rice is a major cereal crop in Himachal Pradesh, a Himalayan state of India, where paddy acreage is about 78,000 ha with a low average yield of 19.62 q ha?1 due to rainfed upland farming. High seeding rates and poor resource-use efficiency of conventional fertilizer nitrogen (N) management practices in rainfed upland paddy have also been major production constraints in rainfed upland ecosystems. To validate and refine the production technology on seed rate and fertilizer N management, the Farm Science Centre, Sundernagar, India, conducted numerous on-farm trials (OFTs) during 2006–2010 under an on-farm participatory technology development approach to enhance resource use efficiency through these resource conservation technologies and boost the paddy productivity in the region. Results of two OFTs conducted during Kharif 2006 in the Mandi District of Himachal Pradesh on different seed rates under different sowing methods on VL Dhan-221 and Sukaradhan-1 (HPR-1156) cultivars suitable for rainfed upland conditions revealed that the seed rate at 80 kg ha?1 sown in rows 20 cm apart resulted in the greatest average paddy productivity to the tune of 25.6 q ha?1 besides greater profitability, followed by a seed rate at 60 kg ha?1 sown in rows 20 cm apart (25.2 q ha?1), over the earlier State Agricultural University (SAU)–recommended practice, that is, seed rate at 100 kg ha?1 in rows 20 cm apart. This refinement in the seed rate was accepted by the participating farmers of the region. The greatest average benefit/cost (B/C) ratio was observed in plots with seed rate at 60 kg ha?1 sown in rows 20 cm apart. Based on these results and data compilation from other locations of the state, now the SAU has refined the seed rate from earlier recommendation of 100 kg ha?1 to 60 kg ha?1 in rows 20 cm apart as well as 80 kg ha?1 through broadcast method under rainfed upland paddy in Himachal Pradesh. Results of two OFTs conducted during Kharif 2009 on integrated nutrient management in rainfed upland paddy revealed that farmyard manure (FYM) at 10 t ha?1 + nitrogen, phosphorus, and potassium (N, P, K) at 15:30:30 kg ha?1 at sowing followed by 15 kg N ha?1 15 days after sowing (DAS) and remaining the N [i.e., 30 kg N ha?1] at tillering (45–50 DAS) resulted in the greatest grain yield of 29.85 and 31.67 q ha?1 in VL Dhan-221 and HPR-1156, respectively, with respective greater yields of 35.99 and 36.51% over farmers’ practice, besides better profitability. To further standardize fertilizer N split doses and assess their effect on paddy productivity, another OFT was conducted during Kharif 2010 under rainfed upland paddy conditions in HPR-1156. The results revealed that NPK at 60:30:30 kg ha?1 (whole of P and K as basal, 50% N at 15 DAS, 25% N each at 45–50 DAS and 70–75 DAS splits) resulted in better grain yield (34.3 q ha?1) and net profitability (?29,786 ha?1) over other treatments. Overall, it is concluded that these resource conservation technologies developed under the OFT participatory approach can enhance the rainfed upland paddy productivity and strongly show that there is dire need to split the N requirement of rainfed upland paddy in 2–3 splits to reduce the fertilizer N losses, enhance resource-use efficiency, and increase productivity and profitability in Himachal Pradesh, India.  相似文献   

10.
Background : Since recently, the traditional rice–wheat rotation systems in Nepal are subject to drastic changes. Progressing urbanisation and shifting consumer preferences drive a replacement of wheat by high‐value vegetables during the cold dry season, particularly in the peri‐urban fringes, while emerging water shortages prevent permanent soil flooding during the monsoon season, leading to partial substitution of lowland rice by less water‐consuming upland crops. Associated changes in soil aeration status affect soil nutrient availability while particularly vegetables enhance the demand for the critically limiting micronutrients boron (B) and zinc (Zn). Aim : In both rice‐ (anaerobic) and maize‐based (aerobic) systems we assessed the differential response of traditional winter wheat in comparison to cauliflower and tomato to applied B and Zn fertilizers. Methods : Experiments were conducted (1) in a pot trial with two contrasting soil types (Acrisol vs. Fluvisol) and (2) in field validation trials at two contrasting sites (representing lowland vs. mid‐hills) in Nepal. Results : The on‐going shift from flooded rice to aerobic maize during the wet season negatively affected dry matter accumulation and grain yield of the dry season wheat, but not of cauliflower and tomato. While Zn application tended to increase wheat yields under field conditions, B application induced no significant effect, irrespective of the soil or production site. However, low to moderate applications of B (2.0–4.4 kg ha?1) and Zn (3.3–4.4 kg ha?1) nearly doubled biomass accumulation and nutrient uptake of vegetables and increased the economic yields of cauliflower and tomato between 8 and > 100%. These responses were generally more pronounced in the Fluvisol than the Acrisol. While overall yields of wheat and temperate vegetables were higher in the cool mid‐hills the relative yield responses to applied B were more pronounced in the lowland than the mid‐hill sites. On average, the partial factor productivities of applied fertilizer were low to moderate in wheat, with 1 and 8 € increase in net revenue per € of investment in B and Zn, respectively. In the vegetables, this partial factor productivity increased to about 4 € €?1 investment with Zn, and reached about 43 € €?1 investment in B, irrespective of the production site. Conclusions : While the application of Zn fertilizers can moderately improve the performance of traditional rice–wheat rotations, B and to a lesser extent Zn application become essential and highly profitable when shifting towards vegetable cropping. The demand for B and Zn fertilizers is foreseen to dramatically increase with progressing urbanisation and the associated shifts in production systems of Nepal.  相似文献   

11.
Phosphorus (P) is an endemic soil constraint to crop production in rainfed semi-arid regions like the 1.82-Mha Pothohar Plateau in Pakistan, where we monitored the P status of rainfed wheat (Triticum aestivum L.) and determined crop responses to P application by broadcast and banding methods. Nutrient indexing of young whole shoots and associated soils revealed severe to moderate P deficiency in most fields. In a 3-year field trial on P-deficient soils, grain yield increases were 130–233% with broadcast and 175–239% with banded P; fertilizer requirement for optimum crop yield was twice as high for broadcasting than banding. Fertilizer use was highly profitable, especially with banding, and increased both available soil P and organic matter. This comprehensive approach of soil–plant nutrient indexing and selective field trials provided a rational economic basis for P fertilizer use in rainfed agriculture and serves as a model strategy for stimulating crop productivity in developing countries.  相似文献   

12.
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   

13.
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   

14.
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   

15.
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   

16.
A five-year cotton–wheat rotation field experiment was conducted on two alkaline-calcareous soils, i.e., Awagat (coarse loamy) and Shahpur (fine silty), to investigate the impact of integrated nutrient and crop residue management on soil and crop productivity. Apparent nitrogen (N) balances were developed. Minimum five-year mean yield (Mg ha?1), obtained with Farmers’ Fertilizer Use (FFU) treatment was: cotton – Awagat, 2.19; Shahpur, 2.45; wheat – Awagat, 3.03; Shahpur, 3.94. With Balance Nutrient Management (BNM), yields increased (P ≤ 0.05) for cotton, 24% in Awagat and 18% in Shahpur soil; and wheat, 37% in Awagat and 24% in Shahpur soil. Maximum crop yields were obtained with Integrated Nutrient Management (INM), i.e., 3–5% higher than with BNM. Crop residue recycling increased the yields further, cotton by 2?7% and wheat by 2–10%. All nutrient management treatments, except for FFU without crop residue recycling, resulted in positive apparent N balances. INM improved SOM and NO3-N, contents.  相似文献   

17.
In low fertility tropical soils, boron (B) deficiency impairs fruit production. However, little information is available on the efficiency of nutrient application and use by trees. Therefore, this work verified the effects of soil and foliar applications of boron in a commercial citrus orchard. An experiment was conducted with fertigated 4-year-old ‘Valencia’ sweet orange trees on ‘Swingle’ citrumelo rootstock. Boron (isotopically-enriched 10B) was supplied to trees once or twice in the growing season, either dripped in the soil or sprayed on the leaves. Trees were sampled at different periods and separated into different parts for total B contents and 10B/11B isotope ratios analyses. Soil B applied via fertigation was more efficient than foliar application for the organs grown after the B fertilization. Recovery of labeled B by fruits was 21% for fertigation and 7% for foliar application. Residual effects of nutrient application in the grove were observed in the year after labeled fertilizer application, which greater proportions derived from the soil supply.  相似文献   

18.
Zinc (Zn) efficient genotypes grow and yield well in Zn deficient environments. The objective of this study was to compare Zn efficiency and seed Zn content among nine winter wheat (Triticum aestivum L.) genotypes grown in chelator-buffered nutrient solutions containing 0 μmol Zn L?1 (?Zn treatment) or 3 μmol Zn L?1 (+Zn treatment). The Zn efficiency of the genotypes ranged from 24% to 46%. Zinc efficiency was positively correlated with shoot dry weight, shoot Zn content, but there was no significant correlation between Zn efficiency and shoot Zn concentration, seed Zn concentration, or seed Zn content. The results suggested that variation in Zn efficiency among these nine wheat genotypes is genetically inherent. Differences in Zn efficiency among these wheat genotypes, which are widely grown in northern China, indicate the potential to breed for wheat genotypes with increased tolerance to soil Zn deficiency.  相似文献   

19.
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   

20.
Since the early 1990s canola (oilseed rape, Brassica napus L.) has become a major crop species grown on the predominantly sandy soils of southwestern Australia. Numerous studies have been undertaken to determine the fertilizer requirements of the crop in the region. This paper reports results of a field experiment conducted at three sites on typical acidified (pH [Ca] ～4.6) sandy gravel soils to identify if molybdenum (Mo), manganese (Mn) or boron (B) were deficient for canola grain production. Different levels of each element, separately or as mixtures, were applied as foliar sprays at mid-flowering. Maximum grain yield responses of ～11–20% to applied Mo, as sodium molybdate (39% Mo), were obtained when 40 g Mo/ha was applied. Maximum grain yield responses of ～13–28% to applied Mn were achieved by applying 1000 g ha?1 Mn, as manganese sulfate (24% Mn). A mixture of 40 g Mo ha?1 and 1000 g Mn ha?1 increased grain yields by ～15–38%. Boron, applied as borax (11% B), sprayed individually or in combination with Mo or/and Mn, had no effect on grain yields. None of the foliar spray treatments had any effect on oil concentration in canola grain. The sprays did not cause any visible damage to foliage. Soil acidification has been shown to induce Mo deficiency for cereal crops in the region and both soil acidification and induced Mo deficiency are alleviated by applying sufficient lime to raise pH of top 10 cm soil to 5.5 or greater, and this strategy should also apply to canola. Further research is required to determine the fertilizer Mn requirements for canola grain production in the region.  相似文献   

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