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1.
As limited information is available on the nutrition of freesias an experiment was carried out to examine the influence of nutrients on foliage and corm growth, and flowering of container‐grown plants. The experiment ran for 10 months using seedlings grown in a peat:sand (3:1,v:v) medium with combinations of varying levels of nitrogen (N), phosphorus (P), potassium (K), and lime. Nitrogen fertilization had a significant effect on many aspects of flowering and growth while the response to P was similar except for a lack of influence on spike production. Fertilization of 600–800 g N m‐3 and at least 200 g P m‐3 are recommended for strong leaf and corm growth with good flowering. There were few significant responses to added K, except in early foliage growth, while liming increased foliage development. High flowering, leaf, and corm growth should be achieved with a media pH of 5.9 and foliar nutrients of 2.2–2.3% N, 0.25–0.30% P, 4.0–4.5% K, 0.65–0.80% calcium (Ca) and 0.20–0.25% magnesium (Mg).  相似文献   

2.
ABSTRACT

Zinc (Zn) deficiency is the most prevalent nutritional disorder in citrus orchards world over. The management strategy of Zn deficiency today is still governed by the efficacy of two conventionally used methods of Zn supply to plants via soil or foliar fertilization. A field experiment with 12-yr-old ‘Nagpur’ mandarin (Citrus reticulata Blanco) orchard was, therefore, carried out during 2004–07 comparing soil application versus foliar application of Zn, each at three levels viz., 100, 200, and 300 g tree?1 with constant doses of N (600 g tree?1), P (200 g tree?1), K (300 g tree?1), and Fe(60 g tree?1) on Haplustert soil type with reference to response on flowering intensity, fruit set, tree volume, fruit yield, changes in soil fertility/leaf nutrient status, fruit quality, and transformation of native soil Zn fractions. Soil application of Zn at all the three levels, produced significantly higher increase in tree volume over foliar application on equivalent rates viz., T1 (2.53 m3) vs. T4 (2.06 m3) and T2(4.30 m3) vs. T5 (2.23 m3). The yield-determining parameters like flowering and fruit set intensity (no. m?1 shoot length) were, respectively, much higher with soil applied (135.74 and 21.90) than foliar applied Zn (31.20 and 11.6). These observations set the favorable conditions required for yield response, e.g., all the three treatments involving soil application of Zn, T1 (32.1 kg tree?1), T2 (52.6 kg tree?1), and T3 (51.8 kg tree?1) were correspondingly superior over T4 (22.5 kg tree?1), T5 (34.3 kg tree?1), and T6 (42.1 kg tree?1) as foliar application treatments. All the three major fruit quality parameters (juice, acidity, and TSS) were likewise more influenced by soil application than foliar application of Zn. Improvements in soil Zn fractions (mg kg?1) viz., exchangeable Zn (0.25–0.60), complex-Zn (2.71 to 4.86), organically bound Zn (0.86 to 2.0), and Zn-bound to carbonates and acid soluble minerals (2.56–4.96) were observed in response to Zn fertilization with treatments T1–T3. On the other hand, foliar applied Zn treatments (T4–T6) produced no such changes in any of the soil Zn fractions.  相似文献   

3.
The effect of ion exchange substrate Biona-312 addition (2 or 5%) on the macronutrients composition of butterhead lettuce cv. ‘Justyna’ plants under conditions of basic (1.5-times) and intensive (3-times concentrated Hoagland solution) mineral nutrition level was investigated. Both experimental doses of Biona-312 introduced into 1.5-times concentrated Hoagland nutrient solution [electrical conductivity (EC) 2.41–2.47 dS m?1] dropped nitrogen (N) content in roots. Simultaneously statistically proven increase in foliar concentration of total sulfur (S) as well as a decrease in phosphorus (P) and potassium (K) contents in lettuce above- and underground organs were observed. The changes in calcium (Ca) and magnesium (Mg) content were insignificant. Ion exchange substrate supplementation into 3-times concentrated Hoagland nutrient solution (EC 6.85–7.30 dS m?1), significantly elevated N and K contents in above- and underground organs, raised the foliar S content, decreased Ca and Mg contents in leaves, as well as dropped P concentration in roots and increased content in leaves.  相似文献   

4.
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   

5.
The aim of this study was to understand impacts of long-term (43 years) fertilization on soil aggregation, N accumulation rates and δ15N in surface and deep layers in an Alfisol. Soil samples from seven treatments were analysed for N stocks, aggregate-associated N in 0–30 cm and the changes in δ15N in 0–90 cm depths. The treatments were: unfertilized control (control); recommended N dose (N); recommended N and phosphorus doses (NP); recommended N, P and potassium doses (NPK); 150% of recommended N, P and K doses (150% NPK); NPK + 10 Mg FYM ha?1 (NPK + FYM) and NPK + 0.4 Mg lime ha?1 (NPK + L). Results revealed that plots under NPK + FYM had ~39% higher total N concentrations than NPK + L in 0–30 cm soil layers. In NPK + L, macro-aggregates had 35 and 11% and microaggregates had 20 and 9% lower δ15N values than NPK + FYM in 0–15 and 15–30 cm soil layers, respectively. However, plots receiving NPK + FYM had ~39% greater deep soil (30–90 cm) N accumulation than NPK + L. These results would help understanding N supplying capacity by long-term fertilization and assist devising N management strategies in sub-tropical acidic Alfisols.  相似文献   

6.
Abstract

A field experiment investigating amendments of organic material including farmyard manure, paper factory sludge and crop residues combined with fly ash, lime and chemical fertilizer in a rice-peanut cropping system was conducted during 1997–98 and 1998–99 at the Indian Institute of Technology, Kharagpur, India. The soil was an acid lateritic (Halustaf) sandy loam. For rice, an N:P:K level of 90:26.2:33.3 kg ha?1 was supplied through the organic materials and chemical fertilizer to all the treatments except control and fly ash alone. The required quantities of organic materials were added to supply 30 kg N ha?1 and the balance amount of N, P and K was supplied through chemical fertilizer. Amendment materials as per fertilization treatments were incorporated to individual plots 15 days before planting of rice during the rainy season. The residual effects were studied on the following peanut crop with application of N:P:K at 30:26.2:33.3 kg ha?1 through chemical fertilizer alone in all treatments, apart from the control. An application of fly ash at 10 t ha?1 in combination with chemical fertilizer and organic materials increased the grain yield of rice by 11% compared to chemical fertilizer alone. The residual effect of both lime and fly ash applications combined with direct application of chemical fertilizer increased peanut yields by 30% and 24%, respectively, compared to chemical fertilizer alone. Treatments with fly ash or lime increased P and K uptake in both the crops and oil content in peanut kernel compared to those without the amendments. Alkaline coal fly ash proved to be a better amendment than lime for improving productivity of an acid lateritic soil and enriching the soil with P and K.  相似文献   

7.
Nutritional status affects the processes of flowering and fruiting of plants. This study was conducted to determine the effects of fertilizer application on flowering, fruiting, and leaf nutrient content of Vanilla planifolia (Jacks. ex Andr). Treatments consisted of the application of grade 10-20-20 nitrogen, phosphorus, and potassium (NPK) fertilizer to the substratum in annual doses of 20, 50, and 100 g/plant plus a monthly application of foliar fertilizer. Two more treatments were foliar fertilization and no fertilization (control). Treatments increased the number of inflorescences and flower buds per plant, as well as the number and weight of fruits per plant, and decreased the abortion of flowers and immature fruits. These effects depended on the type of fertilizer, the amount applied, and the time of evaluation. The best results were obtained with the 100 g/plant/year treatment with an annual production of 1.5 kg of fruits per plant in the second year. Unfertilized plants produced 0.55 kg/plant/year. Differences were also found in foliar content of N, P, K, and copper (Cu) between vegetative and reproductive branches. Application of fertilizer to the substratum appears to improve reproductive parameters of vanilla plants and the production of beans, while foliar fertilization alone was ineffective in increasing crop productivity. Nutrients also seem to translocate from mature leaves to fruit racemes.  相似文献   

8.
ABSTRACT

The effectiveness of nitrogen (N)+ zinc (Zn) soil and foliar fertilizer applications on growth, yield, and quality of apple (Malus domestic Borkh ‘Golden Delicious’) fruit was studied in the Zanjan province, Iran. There were eight treatments 1) control (no fertilizer), 2) soil applied N, 3) soil applied Zn, 4) soil applied N+Zn, 5) foliar applied N, 6) foliar applied Zn, 7) foliar applied N+Zn and 8) combined soil and foliar applied N+Zn. The N source was urea [CO(NH2)2, 46% N] applied at 276 N tree? 1 yr?1 and the Zn source was zinc sulfate (ZnSO4,7H20, 23% Zn) applied at 110 g Zn tree? 1 yr? 1. The soil treatments of N and Zn, were applied every two weeks during June through August (total of 6 times/year) in a 1 m radius around the tree trunk (drip line of trees). The foliar solutions of N (10 g l? 1 urea) and Zn [8 g l? 1 zinc sulfate (ZnSO4)] were sprayed at the rate of 10 L tree? 1 every two weeks at the same times as described for soil applications. The highest yield (49 kg tree? 1), and the heaviest fruits (202 g) were obtained in the soil and foliar combination of N+Zn treatment. The lowest yield (35 kg tree? 1), and the smallest fruits (175 g) were recorded in the control. Nitrogen, and to a lesser extent Zn, foliar application resulted in decreasing fruit quality (caused russeting, and lower soluble solid), but increasing N leaf and fruit concentrations (2.4% DW and 563 mg kg? 1, respectively). There were significant differences among yield and leaf mineral nutrient concentration in different treatments. But there was no significant difference between fruit mineral nutrient concentration (except N). Ratio of N/calcium (Ca), potassium (K)/Ca, and [magnesium (Mg)+K]/Ca in fruits were found suitable for fruit quality prediction. Combining the zinc sulfate with urea in the foliar applications increased the concentration of Zn from 0.7 to 1.5 mg per kg of apple tissue. Leaf N concentration varied during growth season. Foliar applied nutrient can be more efficient than soil applied, but a combination of soil and foliar applications is recommended for apple tree nutrient management.  相似文献   

9.
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   

10.
Rising soil salinity has been a major problem in the soils of Egypt in recent decades. Potassium fertilization and salicylic acid (SA) play an important role in promoting plants to tolerate salt stress and increased the yield of sugar beet crop. A field experiment on sugar beet (Beta vulgaris L.) grown on saline soil was carried out during 2014 growing season in Port Said Governorate, Egypt, to study the effect of potassium fertilization of the soil at applications of 0, 100, 150, and 200 kg potassium (K) ha?1 and foliar spray of SA by solution of 1000 mg L?1, twice (1200 L ha?1 each time) on yield and nutrient uptake. Application of 200 kg K ha?1 in combination with salicylic foliar spray gave the highest root length, root diameter, shoot and root yield, sucrose, juice purity percentage, gross sugar yield, and white possible extractable sugar, nitrogen (N), phosphorus (P), and potassium (K) content, and uptake of sugar beet. The highest increase in sucrose (20%) as well as white possible extractable sugar (184%) was obtained by 200 kg K ha?1 in combination with salicylic foliar spray compared with untreated soil with potassium fertilization and without salicylic foliar spray.  相似文献   

11.
Abstract

Plant nutrition and disease suppression are among the most important management tools for producers of hard red winter wheat (Triticum aestivum L.) in the central and southern Great Plains. This study was conducted to examine the effects of phosphorus (P) (0, 15, and 30 kg ha?1) and potassium (K) (0, 37, and 74 kg ha?1) fertilization, foliar fungicide application, and cultivar disease tolerance on wheat yield, yield components, and severity of leaf rust (Puccinia triticina Eriks.). Compared with no P, fertilizing with P increased yield by as much as 60% (>1.3 Mg ha?1 increase). Yield of cultivars susceptible to leaf rust was nearly 0.6 Mg ha?1 less without K than with K fertilization. Fungicide application resulted in mean yields of 4.8 Mg ha?1 for both resistant and susceptible cultivars, however, yield of susceptible cultivars was suppressed more than yield of resistant ones without fungicide. Although P fertilization had a moderately suppressive effect on leaf rust, the increased yield was primarily due to production of about 50% more heads m?2 apparently from more prolific tillering. Similarly, K fertilization appeared to reduce leaf rust severity and improve yield by increasing kernel weight, but this response may have been related partially to chloride (Cl) in the KCl fertilizer. Correlations suggested that improving dry matter production and N, P, and K uptakes at the boot stage by P and K fertilization can reduce leaf rust severity later in the growing season and increase wheat grain yield. These results indicate that especially P fertilization, but also K fertilization and fungicide application, are important management tools for reducing disease and increasing winter wheat yield.  相似文献   

12.
The effects of soil warming and nitrogen (N) fertilization on nitrogen metabolism and nutrient status of Picea asperata Mast. and Pinus tabulaformis Carr. seedlings were studied in this paper. Infrared heaters increased monthly average soil and air temperature by 2.6 and 2.1°C above the ambient, respectively. Ammonium nitrate (NH4NO3) was added in an amount equivalent to an additional 25?g?N?m?2?a?1. Interestingly, soil warming, N fertilization, and their combination decreased foliar phosphorus (P) and magnesium (Mg) concentration of Picea asperata seedlings, but increased them in Pinus tabulaformis seedlings. Moreover, the combination of warming and N fertilization induced greater increments of amino acid, area-based N concentration and mass-based N concentration, manganese (Mn) and zinc (Zn), and further decreased P and calcium (Ca) concentration in Picea asperata seedlings. However, this phenomenon was not observed in Pinus tabulaformis seedlings. These results indicated that Picea asperata seedlings are more sensitive to the combination of warming and N fertilizer than Pinus tabulaformis seedlings.  相似文献   

13.
ABSTRACT

The effect of three nitrogen (N) application regimes on the color, turf quality, cover, and clipping weights of four different sports type mixtures were evaluated under different wear frequencies for three years in an irrigated field. Nitrogen was applied monthly at rates of low (2.5 g N m? 2), medium (5.0 g N m? 2), and high (7.5 g N m? 2). The turf mixtures were subjected to four different wear treatments at frequencies of zero (control), once per week, once biweekly, and once per month for approximately eight months each experimental year. Wear treatments reduced turf color and quality, cover percentage, and clipping yield. Application of wear every week was detrimental to turf characteristics, whereas wear once every month generally had no significant effect. Nitrogen fertilization resulted in improved color and quality, and increased cover percentage and clipping yield.  相似文献   

14.
Potassium (K) fertilization of cotton (Gossypium hirsutum L.) has been a major research focus the last few years throughout the cotton belt. The objective of this field research, conducted from 1991 through 1994 on two high Mehlich I extractable K (EK) soils, was to evaluate broadcast and foliar applied K for conventional‐ (CT) and no‐tillage (NT) production. Main plot broadcast K rates were 0, 28, 56, and 112 kg K ha‐1. Foliar sub‐plot treatments were a non‐foliar check, KNO3, and Ca(NO3)2. The KNO3 was applied four times per year at 4.1 kg K ha‐1 application‐1. Calcium nitrate was applied at 1.6 kg N ha‐1 to equal the N applied in the KNO3. Extractable K increased annually with broadcast K for both tillage systems and soils and was higher for NT than CT. Lint yields from CT of both soils were increased two of the eight site‐years while yields from NT were increased five of eight site‐years by broadcast K. Three of the NT site‐year yields plus four‐year mean yields of both soils were increased by applying 56 kg K ha‐1, a rate higher than currently recommended for high EK soils. Yield responses to foliar fertilization were from added N rather than the K. Petiole K levels were sufficient so that extra K applied foliarly was not recommended for either soil or tillage system.  相似文献   

15.
Abstract

Granular application of potassium (K) in soils testing high is generally not recommended. However, the effect of foliar K on rainfed wheat (Triticum aestivum L.) under these soil conditions is largely unknown. The objective of this work was to identify the effect of K fertilizer on K use efficiency (KUE), grain yield and yield components of wheat. The data were collected until 2017 in an ongoing trial established in 2007 with eight treatments; two granular K rates (0 and 50?kg K ha?1); two foliar N rates (0 and 3?kg N ha?1); and two foliar K rates (0 and 3?kg K ha?1) in a split-split plot arrangement. Treatments were applied to the same plots each season. Treatment with foliar K resulted in the highest KUE response but the effect size varied according to the accumulated precipitation during the reproductive stage. On average, KUE was enhanced in crop seasons with water constrains (<179?mm) during the growth period but the converse was true as the amount of precipitation increased. In contrast, granular K had no effect on KUE irrespective of precipitation conditions. Application of foliar K increased grain yield as compared to granular K from 2988 to 3089?kg ha?1. This enhancement was attributed to an increased number of grains per head. Therefore, foliar K application to wheat is suitable in a soil testing high K to enhance KUE and grain yield, overall in crop seasons with water constrains.  相似文献   

16.
Abstract

This three-year study (2003–2005) aimed to improve the yield and quality of pastures growing naturally that are colonized by naturally occurring vegetation without agricultural input under hazelnut (Corylus sp.) orchards in the middle and eastern Black Sea regions of Turkey. There were eight treatments: 1) control; 2) fertilizer only (triple superphosphate 44% and calcium ammonium nitrate 26%) (80kg ha?1 P and 60 kg ha?1 N in Samsun; 100 kg ha?1 P and 80 kg ha?1 N in Ordu; 100 kg ha?1 P and 40 kg ha?1 N in Giresun); 3) lime only (calcium carbonate 94%) (3.0 t ha?1 lime in Samsun; 4.5 t ha?1 lime in Ordu and Giresun); 4) early cut only; 5) soil aeration only; 6) fertilizer+lime; 7) fertilizer+lime+early cut; 8) fertilizer+lime+soil aeration, laid out in a randomized complete block design with four replicates at each location. The highest dry matter (DM) yield of kg ha?1 and crude protein content (%) was obtained from the treatments that included fertilizer. There was no difference in DM production between any of the combination treatments that involved fertilizer and the fertilizer alone treatment. Only lime and aeration applications also increased yield compared to control, but not as much as did any treatment including fertilizer. Crude protein content of the pasture ranged from 13.3 to 18.1% across locations. Nitrogen and phosphorus fertilizer are recommended to improve DM yields and herbage quality for pastures under hazelnut orchards.  相似文献   

17.
Abstract

The present study was conducted in the existing germplasm block of gerbera under protected condition at ICAR-IIHR, Bengaluru, India during 2017–2019 to obtain comprehensive information on biomass partitioning, nutrient uptake pattern and flower yields in different genotypes for precision use of critical inputs. The number of leaves (187.6–353.2 m?2?yr?1) and flower stalks (166.9–274.5 m?2?yr?1) varied significantly among genotypes. Specific leaf area (SLA) was similar among Balance, Stanza, Arka Aswha and Terra Kalina cultivars (0.150–0.156?cm2 mg?1). Strong positive influence of SLA on number of flower stalks was evident from the significant correlation (r = –0.774). Significant positive correlations among number of flower stalks and leaves, leaf area and SLA substantiate the flower yield pattern in gerbera. Optimum leaf number per plant was estimated at 18.6, while optimum range was quantified at 14.1 to 22.4. In gerbera genotypes, the partitioning of total aboveground dry biomass to leaves and flower stalks was 46–61% and 39–54%, respectively. The average nutrient removal was quantified at 32.8?g N, 7.3?g P, 78.7?g K, 24.7?g Ca and 4.1?g Mg m?2?yr?1 and the uptake of macronutrients was in the order of K?>?N > Ca > P?>?Mg. The order of micronutrient removal (g m?2?yr?1) was Fe (0.2), Zn (0.08), Mn (0.06) and Cu (0.03). The soil fertility status at uniform management was above optimum. It is clear that leaf number, biomass partitioning and nutrient removal pattern had direct impact on flower stalk yields of gerbera.  相似文献   

18.
Abstract

To examine the nutrient and fertilization needs of Vernonia galamensis, a new oilseed crop, experiments were conducted in the greenhouse with V. galamensis subsp. galamensis var. ethiopica, and var. petitiana. In the first experiment, the plants were grown in soil‐less medium, irrigated, and fertilized daily with 7:3:7 Shefer liquid fertilizer at the rate of 0.5, 1.0, and 2.0 L m?3. Plants in the control group were fertilized every two weeks at a rate 36 times lower than the low treatment. In the second experiment, plants of var. ethiopica were grown under five fertilization regimes with different levels of nitrogen (N) and phosphorus (P)(7:3:7, 14:3:7, 3.5:3:7, 7:6:7, and 7:1.5:7 N:P:K, respectively), applied at a rate of 1.0 L m?3. In the first experiment, control plants of both varieties suffered severe stress affecting all aspects of growth. The three fertilization treatments elicited a uniform response in var. petitiana while var. ethiopica responded differentially, performing optimally under 1.0 L m3 of fertilizer. The growth parameter most stimulated in the case of var. ethiopica was production of primary branches and hence production of flowerheads, but optimal fertilization also had a positive effect on the oil and vernolic acid concentrations. In the second experiment, high N caused a small but significant decrease in biomass as well as plant senescence and drying. Plants grown under high P had slightly more biomass. Low N (3.5:3:7) or low P (7:1.5:7) resulted in fewer capitula. Time of flowering and number of branches were not significantly affected by fertilizer composition. High N caused a significant reduction in oil and vernolic acid yields. It seems that the negative effect of the high treatment in the first experiment was related to N rather than to P levels.  相似文献   

19.
The field experiment on effect of primary treated biomethanated spentwash (PBSW) on physiochemical and biological properties of soil and yield of sunflower (Helianthus annuus L.) on sodic soil was conducted at the Postgraduate Farm, Mahatma Phule Agricultural University, Ahmednagar, India, during 2008–9. The experiment was laid out in a randomized block design (RBD) with nine treatments [control, varying doses of PBSW (30, 60, 90, 120, 150, and 180 m3 ha?1), farmyard manure (FYM) + recommended dose of fertilizer (RDF), and FYM + gypsum at 50% gypsum requirement (GR) + RDF] with three replications. The FYM dose was 5 Mg ha?1. The experimental soil was sodic calcareous, being of the Sawargaon series of isohyperthermic family of Vertic haplustepts with high exchangeable sodium percentage (ESP), low available nitrogen (N) and phosphorus (P), and high available potassium (K). The results revealed that the physical properties [bulk density, mean weight diameter (MWD) of water-stable aggregates, and hydraulic conductivity] of soil were improved in both layers of sodic soil (0–30 and 30–60 cm) as a result of the addition of increased doses of PBSW. The significant reduction in pH, calcium carbonate (CaCO3), ESP and increase in organic carbon, cation exchange capacity (CEC) and electrical conductivity (EC) were observed in both soil layers as a result of the addition of PBSW at 180 m3 ha?1. The changes in chemical properties were also seen in the treatment of FYM + GR + RDF, but it was at par with lower doses of PBSW (30 to 90 m3 ha?1). The microbial populations [bacteria, fungi, actinomycetes, azotobacter, and phosphate-solubilizing bacteria] increased with an increase in the levels of application of PBSW. However, it was maximum in FYM + GR + RDF treatment, and it showed an overall increase up to the flowering stage and thereafter reduced at harvest. The soil basal respiration as mg carbon dioxide (CO2) increased with the increase in levels of PBSW application but it was the greatest in the FYM + gypsum + RDF treatment. Among the PBSW treatments, the greatest activities of soil enzymes (urease, dehydrogenase, and acid phosphatase) under the treatment of 180 m3 ha?1 PBSW were observed at the flowering stage. The available N, P, and K after harvest of sunflower crop were significantly greater in the PBSW treatment applied at 180 m3 ha?1; however, N, P, and K uptake and yield of sunflower were significantly greater in FYM + RDF + gypsum treatment followed by FYM + RDF and 180 m3 ha?1 of PBSW.  相似文献   

20.
Fertilizer recommendations are needed to increase organic vegetable yields. Thus, organic lettuce growth and nutrient uptake was investigated in a randomized block pot experiment with twelve treatments from the factorial structure of three factors: (i) Gafsa phosphate [0 and 200 kg phosphorus pentoxide (P2O5) ha?1], (ii) compost from source separated municipal organic waste (0, 15, and 30 t ha?1) and (iii) limestone [0 and 8 t ha?1 calcium carbonate (CaCO3) equivalent]. Lettuce yield increased with compost application and a first order interaction between lime and phosphate was clear because lime partially replaced the need for phosphate. This was explained by the effect of liming on P availability in acid soils. Nitrogen (N), phosphorus (P), and potassium (K) accumulation increased in lettuces produced with compost or phosphate but only the accumulation of N was increased with lime. This compost is recommended to increase nutrient availability for organic lettuce whereas the need for phosphate fertilization may decrease with liming.  相似文献   

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