首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Among the major nutrients, potassium (K) not only improves yields but also improves quality parameters. Field experiments were conducted to assess the comparative effect of sources and rates of K fertilizer on potato yield and quality on a sandy loam soil. Graded doses of potassium, i.e., 0, 150 and 225 kg ha?1 K2O from sulfate and muriate of potash were applied in triplicate. Recommended dose of nitrogen (N) and phosphorus (P) applied uniformly. Significant increase in tuber yield was observed with 150 kg ha?1 K2O from both the sources over control. Increase in tuber yield with 225 kg ha?1 K2O was statistically non significant compared to 150 kg ha?1. The dry matter and specific gravity were more affected with sulfate of potash (SOP) than muriate of potash (MOP). The quality parameters like dry matter, specific gravity, starch contents, vitamin C, chips color and taste were improved with K application.  相似文献   

2.
Abstract

This study was conducted in the farmer field between the years 2014 and 2015. In this study, 3 doses of potassium (K) (0, 10, and 20?kg da?1) of K2SO4 (50% K2O) fertilizer and 3 doses of humic acid (HA) (0, 20, and 40?kg da?1) (85% HA) were used. Increase in the HA dose reflected significant effects on pH, salt, organic matter, phosphorus, magnesium, iron, and manganese contents of the experiment area at p?p?p?p?p?相似文献   

3.
不同时期施钾对甘薯光合产物运转动力的调控   总被引：1，自引：1，他引：1  
【目的】通过甘薯不同时期施用钾肥的大田试验,探讨不同时期施用钾肥对甘薯光合产物运转动力的调控效应。【方法】选用典型的食用型甘薯品种"北京553",以硫酸钾(K2SO4)为供试肥料,于2011 2012年2个生长季在山东农业大学农学试验站进行大田试验。试验处理为:不施用钾肥(CK)、全部钾肥基施(JS)、全部钾肥封垄期追施(FS)和全部钾肥高峰期追施(GS)。分析不同时期施用钾肥对功能叶光合产物的输出能力、运输茎的农艺特性、源-库间光合产物运输的渗透动力(茎顶-基部间碳水化合物、氨基酸和K+浓度梯度)及块根中光合产物积累特性的影响。【结果】施用钾肥可显著提高块根鲜薯产量和干重,提高块根膨大速率,其中,基施和封垄期追施钾肥处理增幅较大。基施钾肥显著降低生长前期(栽秧后50 d左右)功能叶碳水化合物含量和蔗糖/淀粉比值,提高生长中后期(栽秧后110 d、170 d左右)功能叶中蔗糖和蔗糖/淀粉比值,增幅分别为10.01%和27.14%(2011),16.16%和61.57%(2012),提高该时期功能叶蔗糖的输出能力。基施还提高生长前期基部茎粗,两年增幅均在20%以上,增大光合产物运输的横截面积;基施和封垄期追施钾肥处理提高生长中后期分枝数,基施处理两年增幅的均值为36.53%和48.44%,封垄期追施的为19.60%和46.17%;同时,降低生长中后期源-库距离,提高有效距离(51—200 cm)所占比例。茎顶部到基部间氨基酸和K+浓度逐渐降低,施用钾肥能提高该浓度梯度的降幅,提高渗透动力,以基施和封垄期追施效果较好,其中,氨基酸浓度两处理的平均增幅分别为87.58%和39.56%,K+浓度的平均增幅分别为272.81%和75.58%。基施钾肥显著降低生长前中期茎基部蔗糖和淀粉含量,基施和封垄期追施钾肥可显著降低生长后期茎顶部和基部蔗糖含量,同时降低淀粉含量。【结论】施用钾肥可减少生长前期功能叶中淀粉的合成,保证块根中光合产物的充足供应,扩大运输通道的横截面积,提高茎部运输的渗透动力促进茎基部光合产物的卸载,及时形成较强的库,提高生长中后期功能叶蔗糖含量和可运输态(蔗糖)的比例,增加光合产物运输通道数量,降低运输距离,提高运输有效性,并提高茎部运输的渗透动力,促进茎基部光合产物卸载,促进块根的膨大,形成高产。在本试验条件下,基施钾肥处理最优。  相似文献   

4.
Abstract

Groundnut (Arachis hypogae L.) is the most important oilseed crop of India and it is abundantly grown under rainfed conditions in vertisols of Western India. The objective of this work was to study the effect of potassium (K) basal and foliar fertilization on yield, nutrient concentration in tissue and quality parameters of groundnut. Two varieties, GAUG‐1 (bunch type) and GAUG‐10 (spreading type) were grown during Kharif (rainfed) and Rabi (irrigated) seasons at Junagadh, Gujarat. The experiment compared two foliarapplied K fertilizers (KCl and K2SO4) at two different doses (0.5 and 1.0%) with basal KCl application (0 and 50 kg K2O ha?1). Field soil was highly calcareous (pH 8.2, NH4OAc extractable K 188 kg ha?1 with 40% lime reserve) Vertic ustochrept. The results showed a significant response in pod yield with foliar and soil‐applied potassium as compared to the control treatment. Pod yields were significantly higher when basal and foliar applications were combined. The best results were achieved with foliar application of 1% KCl together with a basal fertilization with 50 kg K2O ha?1. Response to foliar‐applied K was higher in rainfed kharif crop than in irrigated rabi crop. Groundnut variety GAUG‐10 out yielded GAUG‐1. Foliar K application increased plant tissue concentration of K. Foliar fertilization with KCl and K2SO4 did not cause leaf burn. Potassium application improved the crop harvest index and grain quality parameters of boldness, protein and oil contents. Response to K in quality parameters of protein and oil contents of seed was more consistent with foliar applied K2SO4 . The results confirmed that the practice of foliar K nutrition when used as a supplement and not a substitute for standard soil fertilization, is beneficial for groundnut crop in Western India.  相似文献   

5.
A two-year field study was conducted to determine the effect of two zinc (Zn) levels [0 and 10 kg zinc sulfate (ZnSO4) ha?1] in respect with four potassium (K) levels (0, 20, 40 and 60 kg K2O ha?1) on growth, yield and quality of forage sorghum. The soil of the experimental field was loamy sand (Inceptisol), carrying 70, 08, 77, and 0.51 mg nitrogen (N), phosphorus (P), K, and Zn kg?1 soil, respectively. Increasing K levels significantly improved most of the growth, yield, and quality attributes gradually irrespective of the Zn levels. Zinc applied at 10 kg ZnSO4 ha?1 proved significantly better than no zinc application at various K application rates. The benefit of zinc application increased progressively with increasing K rates for most of the parameters studied, indicating significant response of the crop to positive K × Zn interaction in plants in respect with K and Zn application to the soil. Accordingly, 60 kg K2O ha?1 applied with10 kg ZnSO4 ha?1 boosted most of the attributes maximally. It resulted in about 20–40% increase in growth attributes, 25% increase in fresh matter yield, 36–38% increase in dry matter yield, and 38% increase in protein yield compared to the comparable K level applied without zinc. It also enhanced N uptake by 38%, P uptake by 5–19%, K uptake by 40–42%, and Zn uptake by 114–144%. Across the K rates, application of 10 kg ZnSO4 surpassed no zinc application by 30–35% in N uptake, by 8–15% in P uptake, by 33–36% in K uptake, by 120–140% in Zn uptake, by 19–21% in fresh matter yield, by 29–31% in dry matter yield, and by 30–34% in protein yield.  相似文献   

6.
ABSTRACT

To examine the effects of uniconazole (UCZ) on the distribution and transport of photosynthate in sweetpotatoes, three spraying levels of UCZ, 0 (control), 50 and 100 mg L?1, were exposed to an experimental field cultivated with Jishu26 (‘J26?) and Xushu32 (‘X32?) varieties. Compared to control, the distribution of carbon-13 (13C) was significantly higher in the tuberous roots of both varieties treated with UCZ. In addition, UCZ treatments promoted a desirable top-to-base sucrose gradient and significant greater declines in the top-to-bottom amino acid and potassium ion (K+) gradients along the stem. Higher tuberous root yields were found in the UCZ-treated ‘J26? and ‘X32?. In comparison to 50 mg L?1 UCZ, ‘J26? treated with 100 mg L?1 UCZ exhibited significantly higher distribution ratio of 13C in tuberous root, and reductions in the top-to-bottom amino acid and K+ gradients along the stems at 105 and 150 days after planting. Furthermore, 100 mg L?1 of UCZ application exhibited a significantly higher tuberous root yield. For ‘X32?, the two concentrations of UCZ demonstrated no significant differences in these parameters. A reasonable distribution structure of photosynthates that responsible for high yields is associated with the desirable sucrose, ammonia nitrogen (N) or K+ gradient along the stems caused by UCZ application.  相似文献   

7.
ABSTRACT

Glauconite is a potassium (K) bearing mineral, which generally contains 6–10% K2O and mostly available in various natural deposits in India. Glauconite mineral was converted to nano-particle form by grinding in a high-energy ball mill. The release of K from glauconite nano-particle in soil was studied in a pot culture experiment. Five different treatments viz., 0 mg K2O kg?1, 100 mg K2O kg?1, 150 mg K2O kg?1, 200 mg K2O kg?1 used glauconite nano-particle (GNP) as a K source and 100 mg K2O kg?1 from muriate of potash (MOP), were applied in soil to grow maize (Zea mays L.) plant. The highest K+ concentration was observed in shoot at the application of 200 mg K2O kg?1 through GNP and recorded 2 times more K+ concentration in shoots as compared to 0 mg K2O kg?1 treatment whereas 1.1 times more than the MOP treated soil at 5th harvesting stage. Selected plant physiological parameters namely electrical conductivity of plant cell, height, leaf area and nitrate reductase activity were also recorded maximum at 200 mg K2O kg?1 GNP treated soil. Overall, glauconite nano-particle could supply K throughout the growth period and enhanced biomass yield of maize plant without showing any K deficiency symptom.  相似文献   

8.
ABSTRACT

Salt-affected soils expand around the world and become a critical handicap for high crop yield. Saline-sodic soil contributed a major portion in salt-affected soils. Such types of soils have a sizable amount of Na+ in nutrient medium and that reduce the K+ uptake in plants. A hydroponic experiment was performed to investigate the ameliorative effect of different doses of potassium fertilizer (K1 = 0.3, K2 = 0.6 and K3 = 1.2 mM L?1) on rice (Oryza sativa L.) under different ECw (6 dS m?1) and SARw [12 and 24 (mmol L?1)1/2] levels. Application of K+ at elevated levels under saline-sodic conditions improved the concentration of anti-oxidant enzymes, plant physiological, and biochemical attributes by improving the K+: Na+ ratio in plant tissues. Total phenolic content, total soluble protein, and soluble sugar content of rice plant were increased with an increase in potassium dose and saline-sodicity. Maximum K+: Na+ ratios, 4.13 and 2.0 were observed in shoot and root, respectively upon application of K+ at 1.2 mM L?1 in a solution having ECw: SARw level of 6: 12. This study suggested that application of potassium at elevated levels (1.2 mM L?1) has enhanced the rice growth by reducing the harmful effect of Na+ salts on plant physiology, biochemical attributes, and anti-oxidant enzymes under specific saline-sodic conditions.  相似文献   

9.
《Journal of plant nutrition》2013,36(6):1049-1059
Abstract

There is usually a positive yield response when sulfur (S) is applied to rapeseed (Brassica rapa L.) plants grown on S-deficient soils. Recommendations include application of some of or the entire amount of S at planting, but the plant requirement as well as availability of S to rapeseed during its various phenological stages is not well documented. In a field trial, 40 kg S ha?1 was applied as gypsum (CaSO4·2H2O) at planting (T1), during vegetative (T2, 30 days after sowing), flowering (T3, 50 days after sowing), and pod-filling (T4, 65 days after sowing) stages, and in split doses (T5). Biomass accumulation, leaf-area index, and leaf photosynthetic rate were studied at various growth stages. Seed S (sulfate and organic S) and yield parameters were studied at harvest. Sulfur (40 kg S ha? 1) applied in three split doses during different growth stages caused maximum increase in these parameters, followed by T2 and T1. However, no significant discernable difference was observed for the application at planting (T1) and during vegetative stage (T2). No significant response was seen following the application of T3 and T4 when compared with the control (T0). On the basis of these results, we concluded that application of S fertilizer in split doses during growth stages is better than application of the entire amount of S at any stage for obtaining optimum yield of rapeseed.  相似文献   

10.
以津优1号为试材,设K2O施用量分别为0、300、6009、00、1200.kg/hm2.5个处理,研究了不同施钾水平对黄瓜主要品质和有关酶活性的影响。结果表明,在施K2O.300～900.kg/hm2范围内,随着用量的增加,黄瓜叶片和果实中可溶性糖含量与SPS活性均逐渐升高,而K2O用量达1200.kg/hm2时,二者趋于下降。果实中的可溶性糖含量与叶片和果实SPS活性呈显著正相关;而叶片中糖含量与其SPS活性没有明显的相关性。在K2O用量为300～900kg/hm2时,黄瓜果实的Vc含量高于对照,叶片APX活性降低,而果实中的APX活性提高。黄瓜叶片与果实的硝酸盐含量均随施钾量的增加而逐渐降低,K2O用量在0～900.kg/hm2范围内,黄瓜叶片的NR活性较高,且随着钾肥用量的增加而升高;当K2O用量达到1200.kg/hm2时,NR活性明显下降,果实中的NR活性很低,处理间差异不显著。  相似文献   

11.
Abstract

Limited information on the agronomic performance of polyhalite (K2SO4.MgSO4.2CaSO4.2H2O) motivated us to establish two field trials in Sao Paulo, Brazil. The objective was to evaluate the comparative responses of tomato to muriate of potash (MOP), sulfate of potash, potassium magnesium sulfate, and polyhalite at different graded doses of potassium (K) application supplying varied amount of secondary nutrients. Under very low soil K conditions, polyhalite resulted in significantly higher marketable fruit yield, and higher foliar and fruit K and sulfur (S) concentrations than other K sources. This was not the case under medium soil K levels, that is, 101?mg?kg?1. Likewise, polyhalite enhanced postharvest residual soil calcium (Ca), magnesium (Mg), and S than other evaluated sources. Depending on soil nutrient status and the cost of polyhalite, tomato farmers of Brazil could consider polyhalite as an option to meet crop K and secondary nutrient requirements.  相似文献   

12.
Abstract

Nitrous oxide (N2O) emissions were measured and nitrogen (N) budgets were estimated for 2?years in the fertilizer, manure, control and bare plots established in a reed canary grass (Phalaris arundinacea L.) grassland in Southern Hokkaido, Japan. In the manure plot, beef cattle manure with bark was applied at a rate of 43–44?Mg fresh matter (236–310?kg?N)?ha?1?year?1, and a supplement of chemical fertilizer was also added to equalize the application rate of mineral N to that in the fertilizer plots (164–184?kg?N?ha?1?year?1). Grass was harvested twice per year. The total mineral N supply was estimated as the sum of the N deposition, chemical fertilizer application and gross mineralization of manure (GMm), soil (GMs), and root-litter (GMl). GMm, GMs and GMl were estimated by dividing the carbon dioxide production derived from the decomposition of soil organic matter, root-litter and manure by each C?:?N ratio (11.1 for soil, 15.5 for root-litter and 23.5 for manure). The N uptake in aboveground biomass for each growing season was equivalent to or greater than the external mineral N supply, which is composed of N deposition, chemical fertilizer application and GMm. However, there was a positive correlation between the N uptake in aboveground biomass and the total mineral N supply. It was assumed that 58% of the total mineral N supply was taken up by the grass. The N supply rates from soil and root-litter were estimated to be 331–384?kg?N?ha?1?year?1 and 94–165?kg?N?ha?1?year?1, respectively. These results indicated that the GMs and GMl also were significant inputs in the grassland N budget. The cumulative N2O flux for each season showed a significant positive correlation with mineral N surplus, which was calculated as the difference between the total mineral N supply and N uptake in aboveground biomass. The emission factor of N2O to mineral N surplus was estimated to be 1.2%. Furthermore, multiple regression analysis suggested that the N2O emission factor increased with an increase in precipitation. Consequently, soil and root-litter as well as chemical fertilizer and manure were found to be major sources of mineral N supply in the grassland, and an optimum balance between mineral N supply and N uptake is required for reducing N2O emission.  相似文献   

13.
The effect of varying hydrogel (0, 0.5, and 1.0% w/w) supply on some agro-physiological properties, such as dry matter, nutrient contents, chlorophyll contents, proline content, and ionic balance of bean plants in different salt sources and stress due to doses were investigated. Plants were treated with eight salt sources [sodium chloride (NaCl), sodium sulfate (Na2SO4), calcium chloride (CaCl2), calcium sulfate (CaSO4), potassium chloride (KCl), potassium sulfate (K2SO4), magnesium chloride (MgCl2), magnesium sulfate (MgSO4)] and four concentrations (0, 30, 60, and 120 mM doses) for 60 days in a growth media. Salt type, doses, and hydrogel (HG) affected the soil electrical conductivity. Soil salinity affected the parameters considered, and changed the nutrient balance of plants. High salt concentration caused substantial reduction in plant growth. Different salt concentrations negatively affected plant dry weight. The highest decrease of plant root dry weight was obtained with NaCl application followed by Na2SO4, CaCl2, CaSO4, MgCl2, MgSO4, KCl, and K2SO4, and similarly NaCl, Na2SO4, CaCl2, CaSO4, KCl, K2SO4, MgCl2, and MgSO4 in root dry weight. Total chlorophyll and nitrate contents of plants decreased with increasing salt doses, and the lowest value was obtained for NaCl application. Proline contents of plants were increased with increasing salt doses, and the highest value was obtained with the NaCl application. The effects of salt concentrations in nitrogen (N), potassium (K), and phosphorus (P) content of plants were significant. The presence of salt in the growth medium induced an important decrease the macro nutrient of the root and shoot part of plant such as N, P, K, calcium (Ca), and magnesium (Mg) content, but the N and P content of root and shoot part of the plant were increased with increasing of the HG application doses. The highest N and P increases were obtained with the 1.0 HG application for all salt types for both the root and shoots of plants. The HG added to saline soil significantly improved the variables affected by high salinity and also increased plant N and P, reduced soil electricity conductivity, nitrate, proline, and electrolyte leakage of plants, enhanced plant root and shoot dry weight by allowing nutrients and water to release to the plant as needed. The results suggested that HG has great potential for use in alleviating salinity stress on plant growth and growth parameters in saline soils of arid and semi-arid areas. This HG appears to be highly effective for use as a soil conditioner in vegetable growing, to improve crop tolerance and growth in saline conditions. It is intended to confirm the results of these studies by field trials.  相似文献   

14.
施钾对不同肥力土壤玉米钾素吸收、分配及产量的影响   总被引：5，自引：0，他引：5  
采用田间试验, 研究了吉林省高(榆树市)、低肥力(公主岭市)肥力条件下不同钾肥用量对玉米产量、钾素吸收和分配的影响。结果表明, 榆树试验点和公主岭试验点的最高产量施钾量分别为83.3 kg·hm-2和113.9 kg·hm-2, 最佳经济施钾量分别为75.1 kg·hm-2和103.1 kg·hm-2。公主岭低肥力试验点比榆树高肥力试验点的最高产量和最佳经济产量分别提高了3.70%和3.68%。施用钾肥可有效提高玉米干物质最大积累速率和钾素最大吸收速率, 并能提前干物质最大积累速率和钾素最大吸收速率出现的天数。当施钾量超过60 kg(K2O)·hm-2时, 公主岭低肥力试验点的干物质最大积累速率和钾素最大吸收速率均高于榆树高肥力试验点。适宜的钾肥用量有利于提高钾养分由营养体向籽粒的转运量、转运效率及籽粒养分比例, 榆树高肥力试验点籽粒养分比例低于公主岭低肥力试验点, 幅度为0.5%~1.7%。除施钾量60 kg(K2O)·hm-2处理外, 公主岭低肥力试验点的钾肥农学利用率、偏生产力和利用效率等指标均高于榆树高肥力试验点, 分别提高7.3~8.8 kg·kg-1、4.4~8.3 kg·kg-1、1.6%~6.2%。综合考虑提高玉米产量、效益及钾肥利用效率, 高肥力土壤适宜施钾量为75 kg·hm-2, 低肥力土壤上适宜施钾量为103 kg·hm-2。  相似文献   

15.
Citrus, especially Kinnow, fruit yield and quality in Pakistan is not competitive with other countries, which could be mainly attributed to a lack of good nutrient management for citrus orchards. Many of the soils under these orchards have been reported as deficient in potassium (K). Therefore, work was initiated for improving citrus fruit yield, size, and quality through K nutrition management. Experiments were conducted in four districts of Punjab including Faisalabad, Toba Tek Singh, Jhang, and Sargodha and four rates of potash, i.e., 0, 50, 75 and 100 kg dipotassium oxide (K2O) ha?1 were applied using sulfate of potash (SOP) along with recommended rates of phosphorus (P) and nitrogen (N). Soils of all the selected sites were clay loam or sandy clay loam and deficient in K. The leaf analysis also showed that all the selected orchards were deficient in K. Application of K increased the fruit yield and quality but K at100 kg K2O ha?1 was more effective in increasing the fruit weight and size, and peel thickness than other K rates in all the selected orchards. Juice volume and percentage significantly increased when K was applied at 75 kg K2O ha?1 at all sites. Nutrient uptake like K, P, and N enhanced with the increase in K application rate, however, the highest calcium (Ca)+ magnesium (Mg) was recorded at 50 kg K2O ha?1. The results indicated that all rates of K application improved the fruit yield and quality and reduced fruit dropping, however, 75 kg K2O ha?1 rate was more effective as juice volume and percentage, total soluble solid (TSS)/acid ratio and nutrient uptake showed significant improvement.  相似文献   

16.
木薯氮磷钾营养特性及其施肥效应研究   总被引：3，自引：0，他引：3  
以传统木薯品种‘华南205’及新育品种‘华南5号’为材料,通过田间试验,研究了不同时期植株养分含量状况,探讨了施肥措施对不同品种养分含量的影响。结果表明,木薯产量与块根生长阶段(块根形成期、块根生长早期、块根快速膨大期)的氮含量和苗期、块根快速生长期和快速膨大期的钾含量显著正相关(P0.01)。淀粉含量与块根形成期的氮含量显著正相关,与苗期及成熟期的磷含量以及成熟期的钾含量显著负相关(P0.01)。施用氮肥显著提高了木薯的氮含量,施用磷肥和钾肥对氮含量没有显著影响。施用磷肥可使木薯的磷含量小幅提高,而仅苗期达到显著水平,氮肥、钾肥对木薯的磷含量也有一定影响。钾肥显著提高了木薯钾含量,氮肥、磷肥对钾含量没有显著影响。‘华南205’和‘华南5号’的氮含量和磷含量对氮肥、磷肥的响应相对一致,但‘华南205’的钾含量对钾肥的响应明显强于‘华南5号’。‘华南205’和‘华南5号’的氮含量和磷含量水平相对一致,但‘华南205’在块根形成期的氮含量显著高于‘华南5号’,而苗期的磷含量显著低于‘华南5号’,‘华南5号’从苗期至块根膨大期的钾含量均高于‘华南205’,其中块根形成和快速生长期的差异达到显著水平。因此,木薯推荐施肥过程中,在均衡氮磷钾养分的基础上,还需结合考虑品种特性。  相似文献   

17.
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   

18.
Abstract

An experiment was conducted on some soils of Mesa de Guanipa, which are sandy, acid (pH 5.5), and have low levels of available P, K, Ca, and Mg. These soils are located at the Agropecuaria Guanipa farm in El Tigre, Anzoategui State, Venezuela. The main objective was to evaluate rates and sources of P, and rates of K on soybean yield (variety FP‐3), which is an activity of the project “Maximum soybean yields in Venezuela”;, financed by the Potash and Phosphate Institute of Canada. The rates and sources of P were 0, 75, and 150 kg P2O5/ha as triple superphosphate (TSP) and diammonium phosphate (DAP). Rates of potassium as K2O were 0, 60, and 120 kg/ha as potassium chloride (KCl). The experimental design was a randomized complete block with 3 replications and a final plant density equivalent to 400,000 plants/ha. A basic application of nitrogen and magnesium fertilizers was made to guarantee the supply of those nutrients. The soybean seeds were inoculated at planting with NITROBAC to ensure nodule formation. Yield results showed a good response to P application and low response to K. The combination of 150 kg P2O5/ha as TSP and 60 kg K2O/ha as KCl produced the maximum soybean grain yields of 2.857 kg/ha at 12% moisture as well as the highest net return of U.S.$393.9/ha. From the results obtained in this experiment as well as ones to be established during the next 3 years, it is expected that there will be an adjustment in the fertilization program followed by the soybean farmers of Mesa de Guanipa as they are now applying higher rates of K and lower rates of P than that applied in this experiment.  相似文献   

19.
The study was investigated at Agricultural Experimental Farm, Giridih, India during winter seasons of 2007–2008 and 2008–2009. Plants grown with 100% recommended dose of fertilizer (RDF) [nitrogen (N): phosphorus pentoxide (P2O5): potassium oxide (K2O) = 150:60:60 kg ha?1] + AM + Azospirillum (T15) produced maximum chlorophyll, baby cob, and green fodder yield. Root biomass was highest with application of 150% RDF + arbuscular mycorrhizae (AM) + Azospirillum (T16). Co-inoculated plants produced higher chlorophyll, root biomass resulted higher cob and green fodder yield. Biofertilizers supplied along with chemical fertilizers saved 70, 29, and 33 kg N, P2O5 and K2O per hectare, respectively. Nutrient (NPK) uptake was greatest in T15. Residual soil fertility in terms of NPK was recorded maximum in T16. Although, co-inoculated plots built up higher residual soil fertility as compare to sole inoculation. Nutrients use efficiency and benefit cost ratio were higher due to application of 50% RDF with co-inoculants. T16 was most costly whereas T14 (50% RDF + AM + Azospirillum) was most beneficial.  相似文献   

20.
Abstract

Nitrous oxide (N2O) and methane (CH4) fluxes from a fertilized timothy (Phleum pratense L.) sward on the northern island of Japan were measured over 2?years using a randomized block design in the field. The objectives of the present study were to obtain annual N2O and CH4 emission rates and to elucidate the effect of the applied material (control [no nitrogen], anaerobically digested cattle slurry [ADCS] or chemical fertilizer [CF]) and the application season (autumn or spring) on the annual N2O emission, fertilizer-induced N2O emission factor (EF) and the annual CH4 absorption. Ammonium sulfate was applied to the CF plots at the same application rate of NH4-N to the ADCS plots. A three-way ANOVA was used to examine the significance of the factors (the applied material, the application season and the year). The ANOVA for the annual N2O emission rates showed a significant effect with regard to the applied material (P?=?0.042). The annual N2O emission rate from the control plots (0.398?kg N2O-N ha?1?year?1) was significantly lower than that from the ADCS plots (0.708?kg N2O-N ha?1?year?1) and the CF plots (0.636?kg N2O-N ha?1?year?1). There was no significant difference in the annual N2O emission rate between the ADCS and CF plots. The ANOVA for the EFs showed insignificance of all factors (P?>?0.05). The total mean?±?standard error of the EFs (fertilizer-induced N2O-N emission/total applied N) was 0.0024?±?0.0007 (kg N2O-N [kg N]?1), which is similar to the reported EF (0.0032?±?0.0013) for well-drained uplands in Japan. The CH4 absorption rates differed significantly between years (P?=?0.014). The CH4 absorption rate in the first year (3.28?kg CH4?ha?1?year?1) was higher than that in the second year (2.31?kg CH4?ha?1?year?1), probably as a result of lower precipitation in the first year. In conclusion, under the same application rate of NH4-N, differences in the applied materials (ADCS or CF) and the application season (autumn or spring) led to no significant differences in N2O emission, fertilizer-induced N2O EF and CH4 absorption.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

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