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1.
The objective of this study was to evaluate the response of common bean plants to phosphorus (P) applied to the leaves at different growth stages, as a complement to phosphate fertilization at sowing. The experiment followed the 2 × 7-factor randomized block design (RBD) with four replicates. The first factor was fertilization with P at the base with 60 and 120 kg ha?1 of phosphorus pentoxide (P2O5). The second factor was the times and doses of P applied to the leaves: 0.5 or 1 kg ha?1 of P2O5, at the V3 phenological stage; parceled in the following manner: 20% in V3, another 40% in R5 and 40% in R6, or 50% in R5 and 50% in R6; and one treatment with no P2O5 application to the leaves. P-based foliar fertilization increased P content in the grains of plants grown in soils with greater P availability. The lower common bean biomass production under scarce P availability was minimized by the foliar fertilization, as well as its productivity when 1 kg ha?1 of P2O5 was applied to the leaves, 50% in the R5 phenological stage and 50% in R6. The highest productivity was obtained with the application of 0.5 kg ha?1 of P2O5 to the leaves in the V3 phenological stage with the 120 kg ha?1 dose at the base.  相似文献   

2.
Abstract

The experiment was conducted at Kulumsa, South East Ethiopia, using four levels of nitrogen (N) (0, 50,100 and 150?kg N ha?1) and four levels of phosphorus (P) (0, 35, 70 and 105?kg P2O5 ha?1) fertilizers arranged in 4?×?4 factorial arrangements in randomized complete block design with three replications. The available P was increased after harvest due to the application of N and P fertilizer at the rates of 100 or 150?kg N ha?1 and 70 or 105?kg P2O5 ha?1. More specifically, nutrients concentration and nutrient uptake were significantly (p?<?.01) varied among treatment combinations and nutrient use efficiency was declined by increasing N and P after optimum rates. The higher physiological efficiency of N (53.47?kg kg?1) and P (580.41?kg kg?1) and the highest apparent recovery of N (19.62%) and P (2.47%) was recorded from application of 50?kg N ha?1 and P at 70?kg P2O5 ha?1 and the highest agronomic efficiency of N (10.78?kg kg?1) and P (15.25?kg kg?1) was recorded from N at the rate of 50?kg N ha?1 and P at 35?kg P2O5 ha?1, respectively. The combination of N at 100?kg N ha?1 and P at 70?kg P2O5 ha?1 was promising combination that generated highest net benefit 488,878.5 ETB (Ethiopian birr) ha?1 with the highest marginal rate of return (36638%) and gave the highest seed yield (1858.82?kg ha?1) with yield increment of about 57.72% over the control.  相似文献   

3.
Nitrogen (N), phosphorus (P), and potassium (K) deficiencies are a widespread phenomenon throughout the world, and are one of the most common nutritional disorders in Turkish hazelnut (Corylus avellana L.) cultivation. In this research, the effects of macronutrient fertilizers on mineral contents and some biochemical contents of ‘Tombul’ hazelnut (Corylus avellana L.) variety cultivated in the Black Sea Region of Turkey were investigated, and the contribution of these nuts to human nutrition was determined. The trials were carried out at ‘Tombul’ hazelnut orchards, and the hazelnuts were fertilized with five different doses of nitrogen, phosphorus, and potassium in each year for three consecutive years. The basic fertilizers (N, P2O5, and K2O) significantly affected some biochemical contents and mineral compositions of the hazelnuts. In order to improve the biochemical and mineral compositions of hazelnut, 200 kg ha?1 and 400 kg ha?1 N fertilizations, 120 kg ha?1 and 160 kg ha?1 P2O5 fertilizations, and 400 kg ha?1 and 600 kg ha?1 K2O fertilizations could be recommended for practice. According to the daily mineral element requirements, 100 g of hazelnuts provided about 43.5% P, 13.2% K, 19.4% Ca, 37.0% Mg, 0.2% Na, 53.8% Fe, 24.5% Zn, 14.5% B, and 66.7% Mo of the recommended dietary allowances. Cu and Mn contents of 100 g hazelnut were higher than the respective daily requirements. These results indicated that the mineral composition of hazelnut depended not only on the variety but also on the cultivation techniques such as soil condition and especially basic fertilization practices.  相似文献   

4.
The broadcast application of phosphate fertilizers may be more effective than localized application methods for the growth of corn in medium textured oxisol, which have lower phosphorus (P) adsorption capacity. This study aimed to evaluate three phosphate fertilizer application methods at five different doses onto corn grown in oxisol, over two seasons. The experiment was conducted on corn crops in Passos city, Minas Gerais state, Brazil. Stripes with split plots were used to investigate the different application methods where each plot represented double furrow, single furrow, or broadcast application. Within the sub plots, the five doses (0.0, 50, 100, 200, and 400 kg ha?1) of phosphorus pentoxide (P2O5) as granulated monoammonium phosphate (MAP) were applied. Four replications were used. The doses were reapplied in the second cultivation year only for the localized treatments (single and double furrow). The nitrogen in the MAP was held constant among treatments. The corn grain yield in both years was dependent upon both dose and application method, primarily for the single furrow and broadcast methods. In the first year, the broadcast application method of P fertilizer at a estimated dose of 319 kg ha?1 of P2O5 provided a greater accumulated yield over two seasons. Broadcast application is therefore a viable method for growing corn with a reduced spacing distribution on medium textured oxisol.  相似文献   

5.
Leaf mineral content along the crop cycle may explain differences in response to fertilization among strawberry genotypes. A two year field experiment was conducted using responsive (‘Camarosa’, ‘Ventana’) and nonresponsive (‘Camino Real’, ‘Candonga’) to fertilization genotypes under proportional increases in nutrients supply: from a control dose “C” [120 kg nitrogen (N) ha?1, 70 kg phosphorus pentoxide (P2O5) ha?1, 220 kg potassium oxide (K2O) ha?1, 40 kg calcium oxide (CaO) ha?1 and 20 kg magnesium oxide (MgO) ha?1] to “1.33C” and “1.66C” in 2007 and to “1.5C” and “2C” in 2008. Response to fertilization was high (45–120%) at begining of harvesting and low (10-28%) at middle and end of harvesting. Correlation between leaf area and total yields was high (r ≈ 0.73) at begining of harvesting, except on ‘Camino Real’ (late and compact genotype). At begining of flowering and harvesting, responsive genotypes showed higher potassium (K) and lower calcium (Ca) leaf contents than nonresponsive genotypes, accentuated with the fertilization increase.  相似文献   

6.
A field experiment was conducted during the winter seasons between 2004 and 2006 to assess the role of balanced fertilization and bioregulators (foliar-applied brassinosteroid 0.5 mg I?1, thiourea 1000 mg I?1 and kinetin 10 mg I?1) in enhancing the productivity of wheat. Conjoint application of NPKSZn (120 kg N, 40 kg P2O5, 30 kg K2O, 40 kg S, 5.5 kg Zn ha?1) recorded maximum improvements in yield attributes and significantly out-yielded all the fertilization treatments with 14.90, 4.97 and 6.39% increments in grain yield compared with NPK, NPKS and NPKZn treatments, respectively. Nutrient (N, P, K, S, Zn) content and uptake were also improved significantly with balanced fertilization. Among the bioregulators, application of 0.50 mg I?1 brassinosteroid recorded maximum increments in grain yield (14.10%), followed by 10 mg I?1 kinetin (12.31%) and 1000 mg I?1 thiourea (9.92%), over control (4.99 t ha?1). Bioregulators significantly enhanced the uptake of nutrients (N, P, K, S, Zn) over control. NPKSZn treatment also gave the maximum net return (Rs. 51,209 ha?1). Among the bioregulators, brassinosteroid provided the maximum net return (Rs. 47,292 ha?1) and benefit:cost (B:C) ratio (3.37) followed by thiourea (Rs. 45,500 ha?1 and 3.35). Kinetin also provided yield advantage, however, it gave a significantly reduced B:C ratio compared with control.  相似文献   

7.
The study evaluated the effects of phosphorus (0, 20, 30, and 40 kg P2O5 ha?1) and biofertilizers [Rhizobium (Rhizobium leguminosarum bv viciae), plant growth promoting rhizobacteria (PGPR) (Pseudomonas fluorescens), Rhizobium + PGPR, and uninoculated control] in lentil. Application of 40 kg P2O5 ha?1 resulted in the highest number of nodules, nodule dry weight, leghemoglobin content in nodules, chlorophyll content, yield attributes, and grain yield. Coinoculated treatment performed better than uninoculated control, and individual inoculations of Rhizobium and PGPR in terms of all above mentioned parameters. Application of 20 kg P2O5 ha?1 + Rhizobium inoculation gave statistically similar and 20 kg P2O5 ha?1 + Rhizobium + PGPR inoculation gave significantly higher grain yield than that by 40 kg P2O5 ha?1 alone. The use of Rhizobium alone and Rhizobium + PGPR consortium can save not only 20 kg P2O5 ha?1 but also increase the grain yield of lentil.  相似文献   

8.
ABSTRACT

The aim of this research is to assess the effect of the interaction between phosphorus and nitrogen (P × N) in organomineral fertilizer in the nutrition of plants cultivated in a Typic Hapludox. It was used a completely randomized design in a 5 × 5 factorial scheme with four replications. The treatments corresponded to the equivalent of five doses of P (0, 20, 40, 60, and 80 kg ha?1 of P) in interaction with five doses of N (0, 50, 100, 150, and 200 kg ha?1 of N). Three sequential crops of millet were carried out with 40 days of growth each, whose aerial part of the plants was harvested in order to determine the dry biomass and the contents of N and P. After each crop, soil samples were collected from the pot for determination of the forms of P and N. It may be inferred that simultaneous application of N and P into the fertilization does not promote significant changes in the dynamics of N in the soil, but the effect of the interaction is changed over the crop time in the plant. In soil the application of organomineral fertilizers did not show effect of the interaction between P × N on the forms of organic N, inorganic and organic P, except for a difference in the available P, which is the dose of 20P × 200N kg ha?1 with greater efficiency. In the plant, there was interaction between P × N in organomineral fertilizer on the dry biomass of the aerial part of millet from the dose of 20P × 100N, focusing on the dose of 50P × 150N kg ha?1, while the accumulation of P and N starts from the dose of 40P × 100N and 40P × 50N kg ha?1 with an increase (synergy) in both nutrients up to the dose of 80P × 200N kg ha?1.  相似文献   

9.
If soil solution phosphorus (P) optimum levels for plant growth (external P) are known, P adsorption isotherms or their equations could further be used to assess how much fertilizer P may be needed for optimum plants yield (QFPN) by adjusting this known external solution P requirement in the soil (ESPR). Surface soil samples were collected from a farmer's field area and research area. An adsorption study was conducted on Ustic Endoaquerts (S1 soil), Typic Calciargids (S2 soil), and Typic Torripsamments (S3 soil) to develop the two-surface Langmuir-type equations. Phosphorus adsorption data were obtained by equilibrating 10-g soil samples in 100 mL of 0.01 M calcium chloride (CaCl2) containing various amounts of monopotassium phosphate (KH2PO4). Thereafter, 11 P fertilizer rates were calculated by two-surface Langmuir-type equations to adjust different estimated soil solution P levels (EPAS) that were designated as treatments (0.05 to 0.90 mg L?1). Then field experiments on lentil (cv. Niab Masoor 2002) were conducted according to a randomized complete block design (RCBD) on these soils to determine internal (plant tissue), external (soil solution), and fertilizer P requirements. Maximum lentil seed yield (Mg ha?1) was 0.87 with T4 (0.17 mg P L?1) in S1 soil, 1.8 with T3 (0.20 mg P L?1) in S2 soil, and 0.73 with T7 (0.28 mg P L?1) in S3 soil, obtained by applying 170 kg P2O5 ha?1 in S1 soil, 110 kg P2O5 ha?1 in S2 soil, and 78 kg P2O5 ha?1 in S3 soil. Internal P concentrations (%) of the whole plant associated with 95% of maximum lentil seed yield at flowering stage were 0.245, 0.210, and 0.315 in S1, S2, and S3 soils, respectively. Internal P requirements of lentil seed were 0.290 in S1, 0.245% in S2, and 0.380% in S3 soil. The ESPRs for 95% of maximum yield of lentil were 0.16 mg L?1, in S1 soil, 0.23 mg L?1 in S2 soil, and 0.27 mg L?1 in S3 soil. The QFPN estimated from graphs corresponding to these ESPR values were 160 kg P2O5 ha?1 in S1 soil, 125 kg P2O5 ha?1 in S2 soil, and 74 kg P2O5 ha?1 in S3 soil. The QFPNs estimated from corresponding two-surface Langmuir-type equation by using respective ESPR values were 164, 127, and 75 kg P2O5 ha?1 in S1, S2, and S3 soil, respectively. Field-applied P2O5 amounts to adjust soil solution P levels (mg L?1) at 0.166 (T4), 0.229 (T4), and 0.281 (T7) were 170, 126, and 78 kg ha?1 in S1, S2, and S3 soil, respectively. Based on the results of these studies, we propose that QFPNs estimated by graphs against identified ESPR values or calculated by the use of corresponding two-surface Langmuir-type equations are in close proximity to the field-applied P to adjust desired EPAS value. Therefore, either of the two techniques may be used to estimate QFPN for optimum lentil yield. Close  相似文献   

10.
The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T1-control (no fertilization), T2-farmyard manure @ 5 t ha?1, T3-farmers practice (60:30:30 kg N:P2O5:K2O ha?1), T4-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P2O5:K2O ha?1) for targeted grain yield of 4.0 t ha?1, T5-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P2O5:K2O ha?1) plus FYM (5 t ha?1) for targeted grain yield of 4.0 t ha?1 and T6-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P2O5:K2O ha?1) for targeted rice grain yield of 5.0 t ha?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha?1 was achieved in T4 and T6 treatments with 1.59% (4.06 t ha?1) and –3.40% (4.83 t ha?1) deviations, respectively. T4, T5, and T6 significantly increased crop growth, nutrient uptake, available P (Pa) and K (Ka) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T3. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T5 as compared to T6. Highest soil quality index was found in T5 (0.95) followed by T6 (0.90) and, lowest was in T1 (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > Ka (11.3%) > PSM (9.68%) > Na (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.  相似文献   

11.
Abstract

Effective soil diagnostic criteria for exchangeable potassium (Ex-K) combined with inorganic potassium (K) application rates were developed to lower K input in forage corn (Zea mays L.) production using experimental fields with different application rates and histories of cattle manure compost. Two corn varieties, ‘Cecilia’ as a low K uptake variety and ‘Yumechikara’ as a high K uptake variety, were selected from among 20 varieties and tested to make diagnostic criteria for K fertilization applicable to varieties with different K uptakes. The K uptakes increased from 96 to 303 kg K ha?1 for ‘Cecilia’ and from 123 to 411 kg K ha?1 for ‘Yumechikara’ with increasing Ex-K content on a dry soil basis from 0.11 to 0.92 g kg?1 with no inorganic K fertilizer application. The K uptake by corn for achieving the target dry matter yield of 18 Mg ha?1 was estimated to be approximately 200 kg K ha?1 in common between the two varieties. Yields of both varieties achieved the target yield at an Ex-K content of approximately 0.30 g kg?1 with no K fertilization, although ‘Yumechikara’ reached the target yield at a lower Ex-K content. At the low Ex-K content of 0.1 g kg?1, inorganic K fertilizer application at 83 kg K ha?1 was needed to gain the target yield, and apparent K recovery rate for K fertilizer was calculated to be 70% for both varieties. The K uptakes for gaining the target yield by the K fertilization were lower than that by soil K supply. Based on these results, diagnostic criteria of Ex-K and inorganic K application rates were set up as follows: at an Ex-K content of < 0.15 g kg?1, inorganic K fertilizer is applied at 83 kg K ha?1 (100 kg ha?1 as potassium oxide (K2O) equivalent); at an Ex-K content of 0.15–0.30 g kg?1, the application rate is reduced to 33 kg K ha?1 (40 kg K2O ha?1); at an Ex-K content of ≥ 0.30 g kg?1, inorganic K fertilizer is not applied because of sufficient K in the soil. Additionally, we propose that cattle manure compost be used to supplement soil K fertility.  相似文献   

12.
Phosphorus (P) deficiency is one of the most yield limiting factors for crop production in South American soils. Upland rice (Oryza sativa L.) is an important crop in South American cropping systems, including Brazil. A field experiment was conducted with the objective to evaluate 20 upland rice genotypes for phosphorus (P) use efficiency. The P rate used was low (0 kg P ha?1) and high [87 kg P ha?1 or 200 kg phosphorus pentoxide (P2O5) ha?1]. Plant height, shoot dry weight, grain yield, panicle number, 1000 grain weight, spikelet sterility, and grain harvest index were significantly influenced by P and genotype treatments. The P X genotype interaction was significant for grain yield, indicating that genotypes responded differently under two P rates. Overall, grain yield increased by 12% with the addition of P fertilization. Based on grain yield efficiency index, genotypes were classified into efficient, moderately efficient, and inefficient group. The genotypes that were classified as efficient in P use were BRA032048, BRA042094, BRA02601, BRA032051, BRA032033, BRA052015, BRA042156, BRA01600, BRA01506, BRA052023 and BRA042160. The inefficient genotypes in P us efficiency were BRS Primavera, BRA052045, BRA01596, and BRS Sertaneja. Grain harvest index had a significant positive association with grain yield and spikelet sterility had a significant negative association with grain yield, as expected. Average, P-use efficiency of five genotypes was about 17 kg kg?1 (kg grain yield per kg P applied).  相似文献   

13.
The influence of soil properties on phosphorus (P) availability of Louisiana alluvial soils is not fully understood. A pot experiment was conducted in 2011 to evaluate the effect of different P fertilizer rate (0, 34, 67, 101 and 134 kg P2O5 ha?1) on corn growth and development on Perry clay and Commerce silt loam (sil) soils and relate Mehlich-3 and Bray-2 soil test P values with yield, total biomass, and P uptake of corn. The Bray-2 P values were six times higher than Mehlich-3 P values for Commerce sil while they were similar for Perry clay. Bray-2 and Mehlich-3 extractable-P of both soils increased with increasing P rate but only corn grown on Perry clay responded to P rate (P < 0.05). Implementation of appropriate testing procedure for estimating plant-available P in soil is an important component of effective P fertilization guidelines for corn.  相似文献   

14.
A power plant that utilizes turkey manure as fuel to produce energy was built in Benson, Minnesota, and started full energy production in 2007. The plant was built to meet legislative requirements governing the use of renewable sources to generate energy in Minnesota. Although the use of turkey manure as biofuel generates energy, it also results in turkey manure ash (TMA) as a by‐product that contains phosphorus (P), potassium (K), sulfur (S), and zinc (Z) as well as other essential and nonessential elements. A 2‐year study was conducted to compare TMA with triple‐superphosphate and potassium chloride fertilizers as a source of nutrients for alfalfa (Medicago sativa) at three locations: Lamberton, Morris, and Appleton, Minnesota. The soils at Lamberton and Appleton were acidic with P and K concentrations ranging from medium‐high to very high, whereas the soil at Morris was alkaline with high concentrations of P and K. The experiment consisted of a control (0 P and 0 K) and annual and split applications of TMA and fertilizer. Annual TMA and fertilizer rates were 84 kg P2O5 ha?1, 118 kg K2O ha?1, and 34 kg S ha?1. Split rates were 42/42 kg P2O5 ha?1, 59/59 kg K2O ha?1, and 17/17 kg S ha?1. However, because of an overestimation of citrate‐soluble P in 2005 for the TMA, the total amount of available P applied with the TMA for the 2‐year study was 168 kg P2O5 ha?1 compared with 286 kg P2O5 ha?1 for the fertilizer. In the first year, fertilizer resulted in greater alfalfa biomass yield than TMA and the control, whereas in the second year, alfalfa yields with TMA and fertilizer were similar and both more than the control. In 2005, TMA resulted in more copper (Cu) and S tissue concentrations than the fertilizer. In 2006, application of both sources increased tissue P and S concentrations compared with the control. The TMA increased tissue Cu concentration and Zn plant uptake compared with fertilizer. Bray P1–extractable soil P concentrations were less with TMA and control treatments than with the fertilizer treatments. Ammonium acetate–extractable soil sodium (Na) concentrations were greater with TMA than with fertilizer and the control. By the second year, both ash and fertilizer treatments resulted in more K uptake than the untreated control with no difference in K uptake between the two sources or time of application. Both sources were effective in increasing P uptake compared with the untreated control. TMA was shown to be an effective source of nutrients for alfalfa production.  相似文献   

15.
Optimal management practices for nitrogen (N) fertilization is well defined for corn (Zea mays) cultivated during summer (“summer” corn), but not for corn cultivated during the fall (“fall” corn) in the tropics. Two experiments were carried out to evaluate N rates (50, 100, 200, and 300 kg N ha?1), N application timing (pre-planting – PP, V2–V3, and V5–V6) and N split application, once (at PP, V3, and V6), two (at V3+ V6) and three times (at PP+ V3+ V6) in corn cultivated during summer (2014/2015) and fall (2015/2016). Data on corn grain yield (CGY), weight of 1000-grains, leaf N content and values of soil-plant analyses development (SPAD) were collected and analyzed using univariate, multivariate (principal component analysis, PCA) and regression analysis. Results showed that corn growth was affected by N rates and splitting. Corn cultivated during summer presented higher CGY and weight-1000 g than corn cultivated during the fall. The highest yields were obtained with higher N rates on “summer” corn (125 kg N ha?1) than “fall” corn (50 kg N ha?1). Split N-application at vegetative growth stages, V3+ V6, or PP+ V2+ V6, provided higher yields for “summer” corn, while only PP application was a reliable period of N fertilization for “fall” corn. The finding is that corn cultivated during the fall presented a lower response to N and no obvious advantages to split N fertilization when compared to corn cultivated during summer. These optimal management practices for N fertilization in corn production in the tropics depend on soil water availability.  相似文献   

16.
Abstract

The total and available strontium (Sr) contents of the experimental soil in the National Long‐Term Fertilization Trials set up in 1968 in Keszthely were compared in correlation to the Sr content of the Ramann‐type brown forest soil and different long‐term P‐fertilizer treatments. The Sr uptake by lettuce was also studied. Soil samples were taken from the 0‐ to 20‐cm depth in the 32nd year of the experiment from plots given different P fertilizer treatments (0–50–100–150–200 kg P2O5 ha?1 y?1). The total and available Sr content of soils were measured using ICP‐AES. A positive linear correlation was established between the total and available Sr contents of the experimental soils. The total and available soil Sr contents were significantly higher in large dose P‐fertilizer treatments than in case of lower doses. The Sr concentration of lettuce was four to eight times greater than the available Sr content of the soil samples, and Sr accumulation was observed in lettuce leaves.  相似文献   

17.
To develop phosphorus-based agronomic application rates of phytase-diet, bisulfate-amended Delmarva poultry litter in conservation tillage systems, nutrient release dynamics of the organic fertilizer under local weather conditions were investigated. Delmarva poultry litter was placed in polyvinyl chloride columns to a depth of 5 cm and weathered in the field for 570 days. Leachate from the columns was collected and measured for concentrations of various nutrients. Cumulative release of the nutrients as a function of weathering time was modeled, and the nutrient supply capacity was determined. Poultry litter leachate contained high contents of dissolved organic carbon (15–31,500 mg L?1), nitrogen (N 5–7,070 mg L?1), phosphorus (P 5–230 mg L?1), potassium (K+ 2–7,140 mg L?1), and other nutrients. Release of most nutrients occurred principally in the first 100 days, but for P and calcium (Ca2+), it would last for years. The release kinetics of N followed a logarithm equation, while P and K demonstrated a sigmoidal logistic pattern. The nutrient supply capacity of surface-applied Delmarva poultry litter was predicted at 10.9 kg N Mg?1, 6.5 kg P Mg?1, 34.7 kg K+ Mg?1, 5.4 kg Ca2+ Mg?1, and 14.0 kg SO 4 2? Mg?1. The results suggest that Delmarva poultry litter should be applied to conservation tillage systems at 6.6 Mg ha?1 that would furnish 25 kg P ha?1 and 63 kg N ha?1 to seasonal crops. In repeated annual applications, the rate should be reduced to 5.2 Mg ha?1, with supplemental N fertilization to meet crop N requirements.  相似文献   

18.
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   

19.
The interaction between water availability in the soil and fertilizer application rates often strongly affects crop growth. In the current study, the quality of fresh fruit and antioxidant enzymes of tomato crops (Lycopersicon esculentum Mill) were investigated under different irrigation (low water content [Wl]: 50 ~ 60% field moisture capacity (FMC); moderate [Wm]: 70 ~ 80% FMC; and high [Wh]: 90 ~ 100% FMC) and fertilizer conditions (deficit fertilizer [Fl]: 195 kg ha?1 nitrogen (N) + 47 kg ha?1 phosphorus pentoxide (P2O5) and moderate [Fm]: 278 kg ha?1 N + 67 kg ha?1 P2O5) in a solar greenhouse. The results showed that the quality of fresh fruits and the antioxidant enzyme activities in the leaves and fruits were related to the water content in the soil. Deficit irrigation improved the fruit quality and 50 ~ 60% FMC combined with fertilizer application rates of 195 kg ha?1 N + 47 kg ha?1 P2O5 is recommended for tomato crop cultivation under greenhouse conditions.  相似文献   

20.
A field study was conducted at the Research Farm of NWFP, Agricultural University, Pakistan. Chickpea (Cicer aeritinum L.) cultivar, ‘Hassan-2000’, was sown as a winter crop under conventional tillage (CT) or no-tillage (NT) dryland systems in a randomized complete block design with split plot arrangement using four replications. Three levels of phosphorus (P; 0, 80 and 120 kg P2O5 ha?1) were broadcast applied at the time of last plowing and were thoroughly mixed in subplot size of 1.8 × 5 m. About 20% less weed biomass and 2% higher grain yield was recorded under CT than in NT. Plots supplied with P2O5 had higher value of the all the parameters under study except number of plant m?2 when compared with control (no P applied). However, the grain yield response to P beyond 80 kg ha?1 was not positive. CT + 80 kg P2O5 ha?1 was identified as the optimum level for maximum chickpea production under the existing dryland condition where application of herbicides in NT is not possible. Further experiments to study the optimization of P in chickpea production under dryland conditions are required.  相似文献   

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