Effect of sulfur additions on the yield and elemental composition of canola and spring wheat 1

Growth chamber experiments of canola (Brassica napus L.) and spring wheat (Triticum aestivum L.) were conducted using three soils testing low in extractable sulfate (9–12 mg/kg). Experiments were designed to determine how the three soils compared in plant available sulfur (S) and to test the effects of various rates of potassium sulfate (K₂SO₄) and gypsum on the elemental composition and dry matter yield of the two crops. Based upon plant response, the Queens sandy loam soil appeared to have the least amount of plant available S of the three soils. There was no yield increase associated with S applied to either crop. Canola plants in each soil responded to increased applications of S with greater S uptake and considerably lower nitrogen:sulfur (N:S) ratios. Of the three soils used, only the wheat plants grown in the Queens soil responded to S applications through increased S uptake and a lower N:S ratio. Both sources of S were equally effective in providing available S to the plants.     

Comparing the Calcium Requirements of Wheat and Canola

Spring wheat (Triticum aestivumL.) is the major crop species grown in south-western Australia and no responses of wheat to applied calcium (Ca) have been obtained in field experiments though responses have been obtained in glasshouse pot studies for wheat grown on the predominantly sandy acidic soils of the region. Since the mid 1990s canola (oilseed rape, Brassica napus L.) has been grown in rotation with wheat and has often developed symptoms of Ca deficiency when grown on sandy acidic soils in the field. The Ca requirement of canola in these soils is not known and was measured and compared with Ca requirements of wheat in the glasshouse study reported here when 5 amounts of Ca (0–630 mg Ca/pot), as calcium sulfate, were applied.

Application of Ca did not affect shoot production of wheat but increased grain yields by about 25% and 50 mg Ca/pot was required to produce 90% of the maximum grain yield. Two canola cultivars were grown, and both showed no shoot yield responses to applied Ca at early growth (GS1.5). However, at flower bud visible (GS3.5) shoots of triazine tolerant canola cv. ‘Karoo’ showed about 17% increase to applied Ca and required ～47 mg Ca/pot to produce 90% of the maximum yield, while corresponding values for cv. ‘Outback’ were 42% and 185 mg Ca/pot. Both canola cultivars showed large seed (grain) yield responses to applied Ca. Canola cv. ‘Outback’ produced no grain when no Ca was applied and showed ～ 97% increase to applied Ca and required about 462 mg Ca/pot to produce 90% of the maximum grain yield. The triazine tolerant cv. ‘Karoo’ produced about 22% of the maximum grain yield when no Ca was applied, showed approximately 78% grain yield response to applied Ca and required about 475 mg Ca/pot to produce 90% of the maximum grain yield. However, to produce 50% of the maximum grain yield, cv. ‘Outback’ required 250 mg Ca/pot while cv. ‘Karoo’ required about 100 mg Ca/pot. The grain yield response curve for cv. ‘Karoo’ was exponential and that for cv. ‘Outback’ was sigmoid so differences in the response curves were largest when small amounts of Ca were applied and decreased as more Ca was applied. Evidently canola cultivars differ in their ability to access soil and applied Ca providing opportunity to breed and select cultivars efficient at accessing soil and applied Ca. For both wheat and canola the concentration of Ca in dried shoots increased as more Ca was applied and, for each amount of Ca applied, the concentration of Ca in shoots decreased as plants matured. Both canola cultivars consistently had larger concentrations of Ca in shoots than wheat, either when no Ca was applied and for each amount of Ca applied, suggesting canola roots were better able to access soil and applied Ca than wheat roots. The Ca concentration in young wheat (GS15) and canola (GS1.5) shoots that was related to 90% of the maximum grain yield (critical Ca concentration) was 0.33% for wheat and 2.5% for both canola cultivars.     

Effects of seed-placed sulfur fertilizers on canola,wheat, and pea yield; sulfur uptake; and soil sulfate concentrations over time in three prairie soils

The form of sulfur fertilizer can influence its behavior and crop response. A growth chamber study was conducted to evaluate five sulfur fertilizer forms (ammonium sulfate, ammonium thiosulfate, gypsum, potassium sulfate, and elemental sulfur) applied in seed row at 20 kg S ha^?1 alone, and in combination with 20 kg phosphorus pentoxide (P₂O₅) ha^?1, to three contrasting Saskatchewan soils. Wheat, canola, and pea were grown in each soil for 8 weeks and aboveground biomass yields determined. The fate of fertilizer was evaluated by measuring crop sulfur and phosphorus concentration and uptake, and supply rates and concentrations of available sulfate and phosphate in the seed row. Canola was most responsive in biomass yield to the sulfur fertilizers. Sulfate and thiosulfate forms were effective in enhancing soil-available sulfate supplies in the seed row, crop sulfur uptake, and yield compared to the elemental sulfur fertilizer. Combination of sulfur fertilizer with monoammonium phosphate may provide some enhancement of phosphate availability, but effects were often minor.     

QUANTIFYING THE RESIDUAL VALUE OF ZINC FOR CANOLA PRODUCTION DUE TO REMOVAL OF ZINC IN SHOOTS AND GRAIN AND CONTINUED REACTION OF ZINC WITH SOIL

About half of the almost 18 million ha used for agriculture in southwestern Australia were initially acutely zinc (Zn) deficient. Canola (oilseed rape, Brassica napus L.) is a recent crop species grown in the region and there is only limited information on its Zn requirements. In the glasshouse pot study reported here five levels of Zn (0, 0.8, 1.6, 3.2, and 6.4 mg Zn pot^?1) were applied before sowing the first canola crop on an acid sandy loam, and shoot and grain yield responses to applied Zn, and removal of Zn in the shoots and grain, were measured for five successive crops grown to maturity. Before sowing each crop, canola seed was treated with fluquinconazole to successfully control blackleg disease [Leptosphaeria maculans (Desm.) Ces. et de Not.]. Soil samples were collected from each pot before sowing each crop, and after harvesting the last crop, to measure the Zn extracted from soil by diethylenetriaminepentaacetic acid (DTPA) (soil test Zn). Removal of Zn in shoots and grain, and continued reaction of applied Zn by soil, both decreased the effectiveness of applied Zn for successive crops. For all five crops about 71% of the low levels of Zn applied (0.8, 1.6 mg Zn pot^?1) were removed in shoots and grain of the five crops, compared with about 46% for the larger levels of Zn applied (3.2 and 6.4 mg Zn pot^?1). Corresponding values for Zn removed in the grain was about 56 and 30%. Soil test Zn decreased with time since Zn application. The decrease could not all be explained by Zn removed in shoots and grain and was attributed to continued reaction of Zn with soil. For the soil type used, the relationship between either grain yield or total yield (shoots plus grain at maturity), and soil test Zn, was similar for each crop. Therefore, the soil test Zn that was related to 90% of the maximum grain or total yield (critical soil test Zn) was about 0.35 mg Zn kg^?1 soil for each crop.     

Manganese Deficiency in Canola Induced by Liming to Ameliorate Soil Acidity

Applying lime to ameliorate soil acidity has been observed to induce manganese (Mn) deficiency in canola (Brassica napus L.) crops grown on acid sandy soils near Albany and gravelly acid sands of the Great Southern Districts of southwestern Australia. These soils were often Mn-deficient in patches for wheat (Triticum aestivum L.) production when they were newly cleared for agriculture requiring application of Mn fertilizer to ensure grain yields were not reduced by the deficiency. Since then, these soils have acidified and in the 1990s, canola started to be grown on these soils in rotation with wheat and lupins (Lupinus angustifolius L.). These limed soils may now have become marginal to deficient in Mn for canola production. The effect of liming may change the effectiveness of fertilizer Mn. In addition, the effect of liming on the residual value of Mn fertilizer applied to these soils for canola production is unknown. Therefore, a glasshouse experiment was conducted using Mn deficient sand. Three levels of finely-powdered calcium carbonate were added and incubated in moist soil for 42 days at 22±2°C to produce 3 soils with different pH values [1:5 soil:0.01 M calcium chloride (CaCl₂)]: 4.9 (original soil), 6.3, and 7.5. Five Mn levels, as solutions of Mn sulfate, were then added and incubated in moist soil for 0, 50, and 100 days before sowing canola. To estimate the residual value (RV) of incubated Mn for canola production, the effectiveness of the incubated Mn was calculated relative to the effectiveness of Mn applied just before sowing canola (freshly-applied Mn). The RV of the incubated Mn was determined using yield of dried canola shoots, the Mn application level required to produce 90% of the maximum shoot yield, and Mn content in dried shoots (Mn concentration in shoots multiplied by yield of dried shoots). As measured using both yield of dried shoots and Mn content of dried shoots, the residual value of Mn decreased with increasing soil pH and with increasing period of incubation of Mn with moist soil. The critical Mn concentration, for 90% of the total yield of dried canola shoots, was (mg Mn kg^?1) ～17 in youngest mature growth (apex and youngest emerged leaf, YMG), and ～22 for the rest of dried shoots. These values were similar to current critical values for un-limed soils suggesting critical Mn concentrations remain the same for limed soils. Plant testing of canola is recommended if soils are to be limed to ameliorate soil acidity. When plant tests indicate a high likelihood of Mn deficiency, foliar Mn sprays need to be applied to that crop to ensure Mn deficiency does not reduce grain production that year, and fertilizer Mn needs to be re-applied to the soil when sowing the next crop to reduce the likelihood of Mn deficiency for subsequent crops.     

Effect of time of application and amount of nitrogen fertilizer on seed yield and concentration of oil in canola (Brassica napus)

The seed (grain) yield increases (responses) and concentration of oil in seed responses of canola (Brassica napus L.) to applications of fertilizer nitrogen (N), as urea (46% N), was measured in eight field experiments in south-western Australia (SWA). Nitrogen was applied at five different times of application, either at sowing or at three to four weekly intervals until 12–16 weeks (0, 3, 6, 9, 12 or 0, 4, 8, 12, 16) after seedling emergence. Canola, sown in late May to early June, was grown on a range of soil types in different locations of SWA. The greater the amount of N applied and the closer N was applied to the sowing of the canola seed usually gave the largest seed yield increase at both higher rainfall sites (> 500 mm) and lower rainfall sites (<350 mm). Maximum seed yield of canola were reached within nine weeks after seedling emergence. The exception was for a sandy soil (Fluventic Lithic Xerochrept; Brown Tenosol) at Narrogin where applications of N at six, nine, or 12 weeks after emergence gave higher yields compared to N applied earlier mainly due to N leaching in June and July.

The amount of N required for 90% of maximum seed (N_90%Y) yield ranged from five to 58 kg N ha^?1 with the amount depended on location and growing season. For six of the eight sites the higher amounts of N for N_90%Y were required at sowing and three weeks after emergence. Similarly, N use efficiency (NUE, kg grain produced kg N applied^?1) tended was highest for either the N applied at sowing or within three to four weeks after emergence of seedlings. The exception was for a sandy soil at Narrogin where applications of N at six, nine, or 12 weeks after emergence gave higher NUE compared to N applied earlier. N use efficiency decreased as the amount of N increased for all times of N application. Generally, the amount of N applied decreased the oil concentration of canola seed at each time of application. However, the effect of the time of application of N fertilizer on the decrease in oil concentration of canola seed was largest with the highest N level applied at 12 or 16 weeks after seedling emergence. The percentage the oil concentrations decreased as the amount of N applied increased varied with location and growing season. Further research work is required to elucidate the interaction between the growing season, possible rainfall and temperature, and the effects of N on grain yield and oil concentration in seed.     

EFFICACY OF GYPSUM AND MAGNESIUM SULFATE AS SOURCES OF SULFUR TO RAPESEED IN LATERITIC SOILS

A field experiment conducted on rapeseed (Brassica juncea L.) during 2005–2006 in a typical lateritic soil (Alfisol) of West Bengal, India revealed that sources of sulfur viz. gypsum and magnesium sulfate and levels of sulfur (0, 20, 40, 60 kg S ha^?1) have significant influence on grain yield, total biological yield, sulfur concentration in grain and stover, total sulfur uptake, oil content and oil yield and chlorophyll content. The maximum grain yield (18.28 q ha^?1) and oil yield (8.59 q ha^?1) was obtained with magnesium sulfate followed by gypsum yielded the grain yield of 17.99 q ha^?1 and oil yield of 8.22 q ha^?1 at 40 kg S ha^?1. Overall, the best performance was recorded when sulfur was applied at 40 kg S ha^?1 either as magnesium sulfate or gypsum. Results revealed that magnesium sulfate may be considered as the better source of sulfur than gypsum to raise the mustard crop in sulfur deficient acidic red and lateritic soils of West Bengal and if farmers apply either magnesium sulfate or gypsum to soils, the possible deficiency of sulfur and magnesium/calcium in soils and plants can be avoided.     

Soil and Tissue Tests to Predict the Phosphorus Requirements of Canola in Southwestern Australia

Canola (oil seed rape, Brassica napus L.) is now a major crop grown on the predominantly sandy soils in southwestern Australia and knowledge about the phosphorus (P) requirements of the crop in the region is limited. The results of 22 experiments done in the region are reported to determine the relationships between absolute seed (grain) yield response to applied P and (1) soil test P (Colwell sodium bicarbonate procedure) and (2) concentration of P measured in dried shoots at the rosette growth stage. Large grain yield responses to applied P occurred when Colwell soil test P values for the top 10 cm of soil were < 20 mg/kg soil and when concentrations of P in dried shoots were < 3.6 g/kg. The fertilizer P requirements for optimal economic return for canola grain production in the region varied from 10–35 kg P/ha. The 9 different canola cultivars used in the experiments from 1987–2005 had no major effect on the relationship between absolute grain yield response to applied P and soil test P. Application of fertilizer P mostly had no significant effects on either oil or protein concentrations in grain.     

CANOLA OIL PRODUCTION AND NUTRIENT UPTAKE AS AFFECTED BY PHOSPHATE SOLUBILIZING AND SULFUR OXIDIZING BACTERIA

Canola (Brassica napus L.) is a very important agricultural and industrial crop. Hence, the effects of chemical and biological treatments on canola oil production and nutrient uptake, under calcareous conditions, were evaluated in a field experiment. Phosphorus (P) fertilizer and sulfur (S)-oxidizing bacteria (Thiobacillus sp.) increased canola oil production by a maximum of 548 and 335 kg ha^?1, respectively. P-solubilizing bacteria (Bacillus sp.) and Thiobacillus sp. enhanced the uptake of different nutrients including nitrogen (N), P, potassium (K), zinc (Zn), and manganese (Mn). Monthly measurements of soil P indicated that soil P fluctuations can be managed using the applied treatments for proper P fertilization in canola production. The results indicated the important role of chemical and biological (Bacillus sp.) P sources and S-oxidizing bacteria for canola growth and oil production as they resulted in significant increase in canola oil production and nutrient uptake. This can be very beneficial for the farmers and industry.     

Boron nutrition for improving the quality of diverse canola cultivars

Abstract

Canola (Brassica napus L.), is the most important oilseed crop due to high oil contents and low concentration of erucic acid and glucosinolates. In Pakistan, oil seed production is not sufficient to fulfill the needs of the country. Thus, the planned experiment was aimed to evaluate the performance of different canola cultivars i.e. Faisal Canola, Pakola, PARC Canola hybrid and Rainbow at grown under various soil applied boron (B) levels viz., 0, 1, 2?kg ha^?1 under a rainfed environment. The experiment was laid out in randomized complete block design with four replications. Among the canola cultivars, the maximum seed oil contents were recorded in cultivar ‘Pakola’ whereas, higher linolenic acid and protein were recorded in cultivar ‘Faisal canola’ as compared to other cultivars. A synergistic effect was found between various levels of B and quality parameters of the canola seed; as higher concentration of oil contents were found when B was applied 2?kg ha^?1. Conversely the linolenic acid showed the antagonistic behavior with the various B levels. On the other hand, protein contents, oleic acid and erucic acid revealed non-significant differences under different B application rates. In conclusion, the cultivar ‘Pakola’ provided the highest oil content when the B was applied at 2?kg ha^?1; the low concentration of unsaturated fatty acid was observed in ‘PARC canola’ cultivar in the Pothwar region of Punjab, Pakistan.     

The response of a high-yielding canola hybrid to sulfur fertilization in three contrasting Saskatchewan soils

Abstract

Canola (Brassica napus) is the primary oilseed crop in western Canada; however, it is often grown on sulfur (S)-deficient soils. Moreover, canola has a high S demand compared to cereals and, therefore, is particularly sensitive to S deficiency. This study examined the growth and nutrient uptake responses of a high-yielding canola hybrid cultivar to S fertilization when grown on three contrasting soils differing in S fertility, with and without the addition of fertilizer S. The soils were collected from three soil-climatic zones within Saskatchewan (Brown, Black, and Gray) and three different fertilizer S forms were used: ammonium sulfate (AS); ammonium thiosulfate (ATS); and a composite fertilizer containing nitrogen (N), phosphorus (P), and S (NPS; 50-50 blend of sulfate (SO₄) salt and elemental S). Sulfur fertilization increased the canola biomass, along with plant uptake of N, P, and S on all three soils. Fertilizer S use efficiency (i.e. recovery) ranged from 11-75%. For all three soils, the general trend among fertilizer S forms for biomass, nutrient uptake, and fertilizer use efficiency was AS?>?ATS?>?NPS. The greatest differences were observed with the Gray soil, which had the poorest S fertility. Residual soil SO₄ after harvest was greater for ATS and NPS; reflecting continued oxidation of thiosulfate and elemental S to SO₄. Principal component analysis demonstrated the importance of tissue N:S ratio as a key diagnostic measurement related to canola growth and nutrient uptake in S-deficient soils.     

Risks of Boron Toxicity in Canola and Lupin by Forms of Boron Application in Acid Sands of South-Western Australia

Boron (B) deficiency frequently occurs on soils that are low in organic carbon (C) (<1.0% organic C), pH (soil pH_Ca <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.     

Effect of swine manure and urea on soil phosphorus supply to canola

Limited information exists as to the effect of liquid swine manure on soil phosphorus (P) availability in Western Canadian soil. Swine manure is most often applied to meet additional requirements for nitrogen (N) and research to date has emphasized N effects. The effect of swine manure and urea on P supply to canola was investigated under controlled environment condition. Canola (Brassica napus) was grown in pots with manure or urea added to two Saskatchewan soils (sandy loam and clay loam) at 0 and 100 mg N kg^‐1. Plants were grown to maturity, and yield and nutrient content were determined. Phosphorus supply rates in soils were measured in the pots using anion exchange resin membrane probes. Additions of swine manure and urea enhanced canola P accumulation and led to a higher proportion of P in seeds. This response was more evident in the manure treatment than with urea. Soil amended with manure significantly increased N and P supply rates in soils as the manure contains N and P. On the contrary, application of urea significantly increased N supply rate, but led to a slight decrease in the measured soil supply rate of available P. Despite the apparent decrease in soil supply of available P in urea treatment, canola maintained its N:P ratio by increasing P absorption, possibly due to a greater root mass.     

中国青海湖地区草地蝗虫与土壤的关系

A growth chamber study was conducted to determine the relationships between the supply of soil available nitrogen （N） and sulfur （S） and canola （Brassica napus） and wheat （Triticum aestivum L. ‘Biggar＇） N and S uptake and yield in three Western Canadian soils. The suitability of one-hour burial with an anion exchange membrane （AEM） was assessed for its utility as a quick test of the available N：S balance in the soil. Canola and wheat were grown on a Luvisolic soil low in available S and on Brown and Black Chernozemic soils low in both available N and S, with different rates and combinations of N and S fertilizers applied. AEM burial was used to assess soil available nitrate and sulfate supply rates after fertilization. Dry matter yield and N and S concentrations in plant tissues were determined after 6 weeks of growth. The soil available N：S ratio determined by AEM burial closely reflected the relative supplies of available N and S as revealed in the N：S ratios of plant tissue dry matter. The highest yields were achieved where the available N：S ratio in soil and plant tissue ranged from 5 to 13. Thus, a one-hour burial of an AEM probe in the field may be a useful tool to quickly test if a balanced N and S supply is present in the soil for optimum crop yield.     

AMELIORATION OF ZINC DEFICIENCY OF CORN IN CALCAREOUS SOILS OF THAILAND: ZINC SOURCES AND APPLICATION METHODS

A variety of zinc (Zn) fertilizer sources are applied with varied responses on calcareous soils in Thailand. Seed treatment is an alternative method to deliver Zn to corn and alleviate Zn deficiency. To address this Zn delivery methods we conducted greenhouse studies on corn grown in three calcareous soils of Thailand to three Zn fertilizer sources [zinc sulfate (ZnSO₄), Zn-ethylenediaminetetraacetic acid (EDTA) and Zn citrate]. We also evaluated effectiveness of soaking corn seed in three concentrations of ZnSO₄ (0.4, 0.8 and 1.6%) prior to planting compared to soil applied methods. Applications of zinc increased the growth, dry matter yield and zinc uptake of corn with few differences observed among the types of fertilizers. Seed soaking with ZnSO₄ solution also increased Zn uptake, growth rate and yield comparable to soil-applied Zn. Seed soaking prior to planting is an effective and efficient method to supply Zn to corn grown in Zn deficient calcareous soils of Thailand.     

Effect of water stress and nickel application on yield components and agronomic characteristics of canola grown on two calcareous soils

A greenhouse experiment (5 × 2 × 2 factorial arranged in randomized-complete-design with three replicates) was conducted to assess the combined effects of nickel (Ni) and drought stress on growth and yield parameters of canola (Brassica napus L. var. Talaye) grown on two calcareous soils of loamy and sandy clay textures. Treatments consisted of five Ni levels (0, 0.05, 0.1, 0.5 and 1 mg Ni kg^?1 soil) and two levels of water status 100% and 60% field capacity (FC and 0.6FC, respectively). Growth parameters and yield components of plants decreased at drought-stress conditions. Almost all of the studied growth/yield parameters of canola grown on loamy soil were significantly more than those of the sandy clay soil, probably due to the increased capability of loamy soil for supplying the plant water/nutrient requirements. Nickel could positively affect some of the mean growth and yield parameters (e.g., grain yield) over both of the water status conditions. Nevertheless, some of the traits not only increased by Ni fertilization but also decreased compared to that of the control. The positive responses of canola was observed with higher amounts of applied Ni in the sandy clay soil than in loamy soil, e.g., the maximum grain yields of canola grown on loamy and sandy clay soils were obtained with applications of 0.5 and 1 mg Ni kg^?1, respectively. Generally, results demonstrated that Ni could not mitigate the negative effects of drought stress on canola growth or yield components.     

Soil amendments and seed priming influence nutrients uptake,soil properties,yield and yield components of wheat (Triticum aestivum L.) in alkali soils

The effects of soil amendments [i.e., control, gypsum, farmyard manure (FYM), and gypsum?+?FYM] and seed priming (i.e., unprimed, seed soaked in water for 10?hr prior to sowing, and seed soaked in 0.4% gypsum solution for 10?hr prior to sowing) were assessed on growth and yield of wheat (Triticum aestivum L.) crop in alkali soil in northwestern Pakistan. A split plot design was used, keeping priming methods in main plots and soil amendments in sub-plots. The results showed that the effects of soil amendments and seed priming on grain yield, straw yield, harvest index and number of spikes were significant but their interactive effect was non-significant. The highest crop yields and yield index were obtained with gypsum?+?FYM amendments, and seed priming with gypsum solution. The effect on seed emergence, plant height and number of grains per spike was, however, not significant. Grain yield increased by 104% in gypsum?+?FYM treatment over control and by 16.8% with seed primed in water, followed by 8.5% with priming in gypsum solution, as compared to non-priming. The weight of 1000 grains was significantly increased by 35% in gypsum?+?FYM treatment and by 15.8% in gypsum priming. The phosphorus (P) and potassium (K) content increased with soil amendments. Soil pH and gypsum requirement reduced significantly with soil amendments. The blend of gypsum and FYM has improved the properties of salt-affected soil and enhanced fertility for optimum production of wheat in addition to the beneficial effect of seed priming in gypsum solution on crop yield. Using these amendments could be ameliorative in removing the adverse effect of the salt-affected soils, rendering the soil a good medium for plant growth.     

Significant Nitrogen by Sulfur Interactions Occurred for Canola Grain Production and Oil Concentration in Grain on Sandy Soils in the Mediterranean-Type Climate of Southwestern Australia

The nitrogen (N) by sulfur (S) interaction for canola (Brassica napus L.) grain production and oil concentration in grain has been quantified in temperate climates, but it is not known if these results also apply to sandy soils common in the Mediterranean-type climate of southwestern Australia where canola is now a major crop. Seventeen field experiments were undertaken with canola in the region during 1994 to 2005 in which 4 rates of both N (0–138 kg N/ha) and S (0–34 kg S/ha) were applied. Significant grain yield responses to applied N occurred in all experiments and the responses increased as more S was applied. Grain yield responses to applied S only occurred when N was applied and tended to increase as more N was applied. When no S was applied the two largest rates of N applied, 69 and 138 kg N/ha, induced S deficiency reducing grain yields. The oil concentration in grain tended to decrease as more N was applied and increased as more S was applied, particularly when the two largest rates of N were applied. Consequently significant N × S interactions were obtained in all experiments for grain production and in 15 experiments for oil concentration in grain.     

Comparative phosphorus requirement of canola and wheat

The yield response of canola (also known as rape, Brassica napus) and wheat (Triticum aestivum) to applications of phosphorus (P) as single superphosphate was measured in three field experiments in south‐western Australia. The P was banded with the seed while sowing at 4 cm depth. The P requirements of the species was determined from the amount of P required to produce 90% of the maximum yield. Canola consistently required less P than wheat, from 50 to 55% less P for dried tops, and 30 to 58% less P for seed. The P concentration and P content (P concentration multiplied by yield) in dried tops or seed was consistently larger for canola than wheat.     

RESPONSE OF SOYBEAN TO SOIL APPLIED SULFUR AND BORON IN A CALCAREOUS SOIL

A greenhouse experiment with soybean grown on sulfur (S) and boron (B) deficient calcareous soil was conducted for two years in northwest India to study the influence of increasing sulfur and boron levels on yield and its attributing characters at different growth stages (55 days, maturity). The treatments included four levels each of soil applied sulfur viz. 0, 6.5, 13.4, 20.1 mg S kg^?1 and boron viz. 0, 0.22, 0.44, 0.88 mg B kg^?1 at the time of sowing. The highest dry matter yield at 55 days after sowing, DAS (19.3 g pot^?1) and maturity (straw yield ?25.2 g pot^?1 and grain yield ?7.3 g pot^?1) was recorded with B_0.44 S_13.4 treatment combination. The combined applications of sulfur and boron yielded highest oil content with B_0.44S_13.4 (21.7%) treatment level. Chlorophyll ‘a’ and ‘b’ increased significantly with successive levels of sulfur and boron addition at 55 DAS. The mean sulfur and boron uptake in straw and grains increased significantly with increasing levels of sulfur and boron up to 13.4 mg kg^?1 and 0.44 mg kg^?1 and decreased non-significantly thereafter. At both the growth stages, a synergistic interactive effect of combined application of sulfur and boron was observed with B_0.44 S_13.4 treatment level for sulfur and boron uptake in straw and grains.