Effects of Different Application Rates of Pesticides and Chemical Fertilizers on Wheat Stripe Rust and Wheat Yield

[Objectives]The paper was to investigate the effects of different application rates of pesticides and fertilizers on wheat stripe rust and wheat yield.[Methods]Two-factor split block design was adopted.[Results]Different application rates of pesticides and chemical fertilizers would affect the incidence of wheat stripe rust,and further affect the yield of wheat.Triadimefon had no significant effect on wheat yield,and potassium sulfate compound fertilizer had significant effect on wheat yield,while their interaction had no significant effect on wheat yield.There were significant differences in wheat yield among the 15 treatment combinations,which may be due to the fact that the application rate of potassium sulfate compound fertilizer had extremely significant effect on wheat yield.[Conclusions]Under the wheat/green manure/maize zonal rotation system in Bijie,the sowing width of wheat is guaranteed to be 0.5 m under the 1.65 m zonal cropping system,and the sowing rate of wheat is arranged according to the basic seedling of 1.2 million plants/hm^(2).In the early stage of wheat stripe rust,15%triadimefon WP can be sprayed evenly at the dose of 1050 g/hm^(2)by a high-power sprayer in a sunny day.

Evaluation of Soil Potassium Test to Improve Fertilizer Recommendations for Corn

The soil potassium (K) test methodology is under increased evaluation due to the soil sample drying effect, temporal variations of test results and inconsistent crop response to applied K fertilizers. Ten on-farm trials were conducted in 2014 in eastern North Dakota to determine the corn response to different K-fertilizer rates and to assess the variation of soil K test levels between air-dried (KDry) and field moist (KMoist) soil samples during the corn growing season. Significant differences were observed between KDry and KMoist soil K test results. The ratio of KDry/KMoist showed high correlation with cation exchange capacity (r = 0.63, p < 0.10), Organic matter (r = 0.61, p < 0.10) and (Ca + Mg)/K ratio (r = 0.64, p < 0.10) from the 1 M ammonium acetate extractant, while pH, electrical conductivity, clay (%), and soil moisture showed non-significant correlation. On average, KDry resulted in higher soil K test levels than KMoist and pattern of deviation was different for surface and sub-surface soil samples. Soil K analysis of samples collected during the fall and spring showed large enough variations to affect the soil test interpretation category which was used to make fertilizer recommendations. Corn yield increased significantly with applied K fertilizer at only three out of 8 sites with beginning K levels below the current critical level of 150 ppm, and one response was at a site with K level above the critical level. Therefore, use of either the KDry or KMoist method alone may not be adequate to predict K response in some North Dakota soils.

Potato(Solanum tuberosum L.)On-farm Economic Study for Phosphorus and Potassium Fertilizers in Northwestern Ethiopia

In 2018/19,a study was conducted in the East Gojjam Zone of Northwestern Ethiopia to show the current potato cultivation problems relating to inorganic fertilizers at the farm level.The study used a mixture of 0,34.5,and 69 kg P2O5 and 0,100,200,and 300 kg K2O.RCBD(Randomized Complete Block Design)was used with three replications.Using a mixture of 34.5 kg P2O5 and 200 kg K2O yielded a significant total and marketable yield of 49.14 t ha and 48.32 t ha,respectively(with an Ethiopian birr in the net reward of 236,172.40),In addition,this treatment surpass other treatments and produced a marginal rate of return that was higher than the least acceptable marginal rate of return.As a result,it is recommended that a combined fertilizer application method be used to optimize the economic return from potato production in the study area.

Effects of Potassium Fertilizer on Water-Soluble Carbohydrate Content of Timothy (<i>Phleum pratense</i>L.), Silage Fermentation, Nutritive Values, and Nutrient Intake

The objective of this study was to examine the effects of potassium fertilizer (standard (S) and high (H) levels) on water-soluble carbohydrate (WSC) content of timothy (Phleum pratense L.), silage fermentation, nutritive values, and nutrient intake. The silage treatments were as follows: S level without inoculant (SC), S level plus inoculant (SI), H level without inoculant (HC), and H level plus inoculant (HI). The K content was increased by 14.5% in timothy grown with the H level compared with the S level. The WSC contents of the S and H treatments were 75.9 and 66.1 g·kg-1 dry matter (DM), respectively. The silage fermentation quality was low with both SC and HC treatments. The addition of inoculant significantly improved the fermentation quality in SI and HI treatments. The addition increased the DM and organic matter digestibilities of silage. The total digestible nutrient (TDN) content of silage was highest with the HI treatment. The DM, TDN, and digestible energy intakes with the SI and HI treatments were improved compared with the SC and HC treatments, respectively. This study demonstrated negligible effects of K fertilizer levels and significant effects of the lactic acid bacteria inoculant on the fermentation quality, nutritive values, and feed intake of silage.

Soybean Seed Protein, Oil, Fatty Acids, and Isoflavones Altered by Potassium Fertilizer Rates in the Midsouth

Previous research has shown that the effect of potassium fertilizer on soybean ([Glycine max (L.) Merr.] seed composition (protein, oil, fatty acids, and isoflavones) is still largely unknown. Therefore, the objective of this research was to investigate the effects of potassium application on seed protein, oil, fatty acids, and isoflavones under Midsouth environmental conditions. A three-year experiment was conducted in two locations (Milan, TN and Jackson, TN). Potassium (K) rates were applied in the form of K2O at a rate of 0 (Control, C), 45 (T1), 90 (T2), 134 (T3), and 179 (T4) kg·ha-1 in a randomized complete block design. The results showed that increasing the K application rate did not result in consistent effects on yield. However, increasing K application rate did increase protein, oleic acid, and individual and total isoflavone concentrations at both locations in 2008 and 2009. In Jackson in 2010, the increase of K rate did not change oleic acid, but resulted in an increase in glycitein and genistein isoflavone concentrations. In 2010, increasing K application rate increased protein concentrations, decreased individual and total isoflavones, and did not change oleic acid concentration at Milan. At the highest rate of K, 179 kg·ha-1, yield and some seed composition constituents were negatively impacted. Generally, K concentration in leaves at V5, R1, R3, and seed at harvest maturity stage (R8) increased with the increase of K rate applications. The research demonstrated that K application can alter seed composition, but this alteration depended on location, environmental stress factors, mainly heat and drought, K level in soil, and K application rate. Higher rates of K application may negatively impact seed composition constituents.

Effects of Nitrogen-phosphorus-potassium Combined Fertilization on Rice Yield and Fertilizer Use Efficiency in Jianghan Plain

[Objectives]This study was conducted to explore the rational formula for rice fertilization in Jianghan Plain.[Methods]An experiment on the combined application of nitrogen,phosphorus and potassium fertilizers was carried out in Jianghan Plain,an important rice producing area in Hubei,with a total of five treatments to study the effects of nitrogen,phosphorus and potassium fertilizers on the fertilizer use efficiency and yield of rice.[Results]Fertilization had a significant effect on improving rice yield,and nitrogen fertilizer had the greatest effect on rice yield,followed by potassium fertilizer and phosphorous fertilizer.[Conclusions]This study provides a scientific basis for the application of rice fertilizers and the reduction and efficiency improvement of chemical fertilizers in Jianghan Plain.

Effect of nitrogen fertilizer on the uptake and utilization of potassium by various rice varieties in purple soil

Nitrogen and potassium are important nutrientelements for rice.Besides supplied by the or- ganic manure,potassium nutrition of ricecomes dominantly from purple soils in Sichuanbasin.Potassium exists abundantly in mineralforms in the purple soils.Availability of soilpotassium for crop depends on the potassiumforms,the uptake ability of crops,and fertiliz-er practices.A pot culture experiment wasconducted to study the kinetics of potassiumuptake in the purple soil(total N 22.64g·kg,total K 24.36g·kg,available N 102.6mg·kg,available K 140.6mg·kg,acidsoluble K 936.0mg·kg,and pH 6.8).Ma-terials used were three Fhybrid rices,Eryou

Influence of Potassium Fertilization on Yield and Quality of Foliar Vegetable Crops

Over a period of two years , field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv. Lu-Bai 3), autumn greens (B. chinensis L., cv. Piao-Geng-Bai), winter greens (B. var. rosularis Tsen et Lee, cv. You-Dong-Er), and summer greens (B. chinensis L., cv. Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0-300 kg hm-2 for Chinese cabbage, 0-150 kg hm-2 for autumn and winter greens and 0-180 kg hm-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens , respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.

The effects of straw‑returning and inorganic K fertilizer on the carbon–nitrogen balance and reproductive growth of cotton

Background:Many studies have indicated that straw-returning could meet part or even all of the potassium(K)demand for crop growth in the field,but few have compared the effects of crop straw as K source and inorganic K fertilizer on carbon–nitrogen(C–N)balance of cotton and the reproductive growth.To address this,field experiments were conducted using the cotton cultivar,Siza 3,under there treatments(CK as control group one,no crop straw and inorganic K fertilizer were applied;K150 as control group two,150 kg·ha^(-1) of K2O was applied;and W9000,9000 kg·ha^(-1) wheat straw,which could provide K2O about 150 kg·ha^(-1),was incorporated into soil).Results:Although the final reproductive organ biomass did not differ between W9000 and K150,W9000 had a higher ratio of reproductive organ biomass to total biomass(RRT),suggesting that straw-returning was more conducive to the allocation of biomass to reproductive organs.The theoretical maximum biomass of reproductive organ was higher,but the average and maximum accumulation rates of reproductive organ biomass were 2.8%∼8.3%and 2.5%∼8.2%lower under W9000 than K150.Also,the duration of rapid-accumulation period for reproductive organ biomass(T)was 2.0∼2.8 d longer under W9000 than K150,which was a reason for the higher RRT under W9000.Straw-returning altered the dynamics of leaf K with the growth period,so that W9000 had a more drastic effect on leaf C metabolism than K150.Consequently,lower soluble sugar/free amino acid and C/N ratios were measured under W9000 than K150 at boll-setting(BSS)and boll-opening(BOS)stages.Higher leaf net photosynthetic rate,sucrose phosphate synthase and sucrose synthase activities,and lower acid invertase activity were observed under W9000 than K150 at BSS and BOS and these were more conducive to sucrose accumulation.However,less sucrose was measured under W9000 than K150 at these stages.This should be because straw-returning promoted the assimilate transport capacity when compared with inorganic K fertilizer application,which also explained the higher RRT under W9000 than K150.The lower acid invertase activity under W9000 inhibited the conversion of sucrose to other sugars,hence lower contents of soluble sugar and starch were measured under W9000 than K150.Conclusion:Under low K condition,crop straw as K source can increase the assimilate transport from source to sink,leading to lower C/N ratio in leaf and higher allocation of biomass to reproductive organs than inorganic K fertilizer.

Yield and Quality Responses of Selected Solanaceous Vegetable Crops to Potassium Fertilization

Over a period of two years, field experiments were conducted on two silty loam soils grown with four solanaceous vegetable crops of eggplant (var. serpentinum Bailey), tomato (var. commune Bailey), sweet pepper (var. grossum Bailey) and chilli (var. lengum Bailey), respectively. Each experiment included four treatments with from low to high doses, 0-450 kg ha-l for eggplant, tomato and sweet pepper, and 0-270 kg ha-1 for chilli, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One CK treatment without K, N and P fertilizers applied and one treatment of K fertilizer in the form of muriate of potash (MOP) applied at the high level (450 kg ha-1) together with N and P fertilizers were included in the experiments of eggplant, in order to compare the effects of SOP and MOP. The fruit yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. The dry matter and vitamin C contents in fruits of tomato, sweet pepper and chilli, and the sugar content and the titratable acidity level of tomato fruits were increased, and the S/A ratio (ratio of sugar content to titratable acidity) of tomato fruits were decreased by K fertilization, indicating that K fertilization could improve the fruit quality of the solanaseous vegetable crops. However, the high rate of K fertilizer might lower the dry matter and vitamin C contents of tomato fruits and sweet pepper fruits. SOP was more effective than MOP in increasing the yield and quality of eggplant fruits at the high fertilization rate; therefore, the choice of applying SOP may be better for high levels of K fertilization.

Effect of Fertilizer Application on the Yield of Walnut (Juglans regia L.)

[Objectives] This study was conducted to explore the fertilization ratio of walnut, so as to provide a basis for rational fertilization of walnut. [Methods] Under the condition of gravelly yellow soil in Chaotian District, Guangyuan City, the orthogonal design of L_9(3~4) was used to test the fertilization ratio of nitrogen, phosphorus and potassium fertilizers. [Results] The effects of nitrogen, phosphorus and potassium fertilizers on walnut yield ranked as phosphate fertilizer>potassium fertilizer>nitrogen fertilizer. The different treatments had great effects on the yield of walnut, and for the land with gravelly yellow soil, the suitable annual fertilization amount of walnut was urea 1 200 g/plant + calcium superphosphate 1 500 g/plant + potassium sulfate 940 g/plant. [Conclusions] This study provides a theoretical basis for rational fertilization of walnut in Sichuan Province.

Effects of Long-term K Fertilizer Application on the Crop Yield and K Distribution of Soil Aggregates in a Paddy-Upland Rotation System

[Objective]A long-term paddy-upland experiment was conducted to evaluate the effects of the recommended amount of potassium( K)fertilizer on crop yield,distribution of soil aggregate,and soil available K content. It was mainly to ascertain the distribution of K in the soil aggregate components in the paddy-upland rotation system,and then to provide theoretical basis for soil structure improvement,K pool management,and reasonable application of K fertilizer. [Method]There were 2 treatments selected,namely,NP(-K) treatment and NPK( + K) treatment in this study. Then the effects of K fertilizer application on the yield,available K content,and aggregate distribution in the middle rice-winter rape rotation system were analyzed. [Result]The results showed that the output of the crop rotation was affected by the year and fertilization. Compared with NP(-K),the average yield increases of rice and winter rape after application of K fertilizer were 0.51 and 0.33 t/hm2,with the increments of 7.5%and 14. 1% respectively. The long-term application of K fertilizer( 7 a) had no significant effects on the distribution of soil aggregates but could significantly increase the water-soluble K content and available K content at depths of 20-30 and 30-40 cm,and available K content of aggregates in each particle size. In addition,the balance of available K at the 10-20 and 30-40 cm of soil layers was the most significant through calculation of surplus-deficit value of available K in agglomerates of different soil layers. [Conclusion]Compared with the initial available K content in the farmland in 2011,the current K fertilizer application could lead to that farmland K content continues to decline. Therefore,we should pay attention to straw returned and supplement of organic K fertilizer,to maintain crop rotation system's productivity and soil K balance.

2种常用肥料在马铃薯种植条件下肥力转化速率研究

[目的]研究2种肥料在土壤中的转化时间,从而判断养分供给时间和能力,为确定科学施肥时间提供数据支持。[方法]以马铃薯生产中常用的2种肥料为处理,分别是硫酸钾、磷酸二铵。并设置3个土壤含水量处理,分别为25%、35%、45%。设定取样时间,测定肥料剩余量并计算肥料的溶解量和溶解率。[结果]磷酸二铵和硫酸钾分别在施肥后第5天和第56天时溶解量超过或接近50%,可将其标定最佳养分吸收期。磷酸二铵施入21 d后,肥料不再转化,整体上随着土壤水分含量的提高,磷酸二铵溶解能力增强,养分供应能力变大,但持续供养能力变弱。试验周期内硫酸钾养分释放比较平均,在土壤含水量25%和35%条件下,施肥后28 d内为养分高效供应期,28 d后养分供应趋于稳定。在土壤含水量45%条件下,施肥后49 d内为养分高效供应期。整体上看,含水量45%更有利于硫酸钾高效供养时间的延长。[结论]可将磷酸二铵和硫酸钾的溶解能力作为肥料养分供应的指标,但只能应用于矿质元素类肥料,因有机肥料溶解后还涉及矿质化过程,对有机类肥料不具备指导意义。

氮、磷、钾配施对葛根生长及品质的影响

为探明氮、磷、钾肥配施对葛根生长及品质的影响,为葛根高效栽培提供合理的施肥技术支撑和理论依据,采用L_(9)(3~4)正交试验设计,研究氮、磷、钾配施对葛根产量和主要功能成分的影响,明确研究区葛根氮、磷、钾的最佳施用量。结果表明,不同施肥方案对葛根产量和功能成分的影响显著,其中以N_(3)P_(1)K_(2)(N 270kg/hm^(2),P_(2)O_(5)45 kg/hm^(2),K_(2)O 90 kg/hm^(2))处理的产量和总黄酮含量最高,分别为2.13 kg/株和83.10 mg/g;N_(1)P_(3)K_(2)(N 90 kg/hm^(2),P_(2)O_(5)135 kg/hm^(2),K_(2)O 90 kg/hm^(2))的葛根素含量最高,为24.85 mg/g,N_(1)P_(2)K_(3)(N 90 kg/hm^(2),P_(2)O_(5)90 kg/hm^(2),K_(2)O 135 kg/hm^(2))处理的大豆苷和大豆苷元含量均为最高,分别为22.96和2.55 mg/g。氮、磷、钾肥配施对葛根产量和葛根素含量影响的大小顺序为氮肥>钾肥>磷肥。以葛根产量为目标的最佳施肥量为N 270 kg/hm^(2)、P_(2)O_(5)135 kg/hm^(2)、K_(2)O 90 kg/hm^(2),以葛根品质提升为目标的最佳施肥量为N 180 kg/hm^(2)、P_(2)O_(5)135 kg/hm^(2)、K_(2)O 90 kg/hm^(2)。

中国三大棉花种植区域土壤速效钾丰缺指标及推荐施钾量研究

为给西北内陆棉区、长江流域棉区和黄河流域棉区棉花的钾肥施用提供科学依据,采用“零散实验数据整合法”“反正弦-对数矫正模型”以及“养分平衡-地力差减法”,开展了上述三大棉区棉花土壤速效钾丰缺指标和推荐施钾量研究。结果表明,中国三大棉区土壤速效钾丰缺指标均可划分出5级,西北内陆棉区第1~5级丰缺指标为≥418、166~418、111~166、80~111和<80 mg/kg;长江流域棉区第1~5级丰缺指标为≥357、128~357、81~128、56~81和<56 mg/kg;黄河流域棉区第1~5级丰缺指标为≥213、129~213、102~129、85~102和<85 mg/kg。三大棉区土壤速效钾临界值分别为166.0、127.2和128.4 mg/kg。当钾肥当季利用率为50%,籽棉(皮棉)目标产量为2.5~9.0(1.0~3.6)t/hm^(2)时,第1~5级土壤的推荐施钾量依次为0、30~108、60~216、90~324和120~432 kg/hm^(2)。

我国籽实和饲草燕麦土壤钾素丰缺指标与推荐施钾量初步研究

为了给我国燕麦测土施钾提供科学依据,本研究采用“零散实验数据整合法”和“养分平衡-地力差减法新应用公式”,开展了我国燕麦土壤钾素丰缺指标与推荐施钾量研究。结果表明,我国燕麦土壤速效钾第1~3级丰缺指标依次为≥258、117~258和<117mg/kg,全钾第1~4级丰缺指标依次为≥31、21~31、11~21和<11 g/kg。当钾肥当季利用率40%~60%时,目标产量1.5~6.0t/hm^(2)籽实燕麦第1~4级土壤推荐施钾量分别为0、10~60、20~120和30~180kg/hm^(2);目标产量4.5~15t/hm^(2)饲草燕麦第1~4级土壤推荐施钾量依次为0、18~90、36~180和54~270kg/hm^(2)。本研究初步建立了我国籽实和饲草燕麦土壤钾素丰缺指标推荐施肥系统,为我国燕麦测土施钾奠定了科学基础。

供钾水平对宁南山区花椰菜产量及钾素平衡的影响

【目的】为宁夏冷凉花椰菜生产中钾肥合理施用提供科学依据。【方法】以宁夏冷凉主导花椰菜为试验材料,设置0(K_(0))、10(K_(10))、20(K_(20))、30(K_(30))、40 kg/667m^(2)(K_(40))5个施钾水平,通过田间试验,研究供钾对露地花椰菜产量、钾素吸收分配利用及土壤根层钾素质量与平衡的影响。【结果】供钾显著增加花椰菜产量,增产率在5.32%~16.24%,供钾水平与花球产量呈极显著的二次抛物曲线关系,最高产量为3 529.43 kg/667 m^(2),最佳供钾水平为24.28 kg/667 m^(2)。在苗期和莲座期茎叶是花椰菜钾元素的累积中心,不同处理茎叶分配比例在49.67%~90.49%,进入成熟期花球是花椰菜钾元素的累积中心,不同处理花球累积分配比例在42.25%~53.73%,整株花椰菜钾素累积量苗期以K_(30)处理最高,莲座期和成熟期均以K_(20)处理最高,较对照分别显著提高69.40%、79.38%。钾肥利用效率为21.77%~40.31%,以K20处理的钾肥利用率、贡献率及农学效率均最高,分别为45.28%,21.31%、38.670 kg/kg。供钾水平低于20 kg/667 m^(2)时,土壤钾素平衡表现为亏缺,供钾水平超过30 kg/667 m^(2)钾素盈余由负转正,再继续投入钾肥,钾素盈余。【结论】综合考虑花椰菜钾素吸收利用分配与产量和土壤钾素有效性与菜田钾素收支平衡等因素,建议宁夏南部山区花椰菜适宜的供钾水平为21.82~29.24 kg/667 m^(2)。

氮、磷、钾肥对紫穗槐幼苗根叶化学计量特性的影响

探讨紫穗槐根和叶化学计量特性对养分的适应性,为豆科植物施肥和限制模式的研究提供依据,采用三因素(氮(N)、磷(P)、钾(K)),三水平(N1,N2,N3,P1,P2,P3,K1,K2,K3)的施肥处理,测定紫穗槐幼苗根和叶的碳(C)、氮、磷、钾含量,分析根和叶各元素之间的关系。结果表明,在P、K添加下,叶片比根系有更强的响应,根系对N添加有更强的反应。叶片和根N含量、根N/K和N/P随施氮水平的增加而显著增加,根P/K、叶P/K和根C/N显著降低。随着施磷量的增加,叶片N、P、K含量、根P含量、根N/K和P/K显著增加,叶N/K和叶N/P显著降低;根和叶K含量随施钾量的增加而显著增加,根N/K和P/K、叶N/K和P/K显著降低。叶P含量与根P含量、叶K含量与根K含量呈显著正相关,叶C、N含量与根C、N含量之间的关系不显著,而叶根N、P、K含量分别与相应的C/N、N/P和N/K呈显著负相关。叶和根的C/N之间的关系不显著,而叶的N/P、N/K和P/K之间的相关性显著。隶属函数分析结果表明,在紫穗槐C、N、P、K含量的累积方面,N2处理最佳。N的添加导致P对叶片和根的限制;P的添加导致N对叶片和根系的限制;K的添加并没有改变限制模式。研究结果可为紫穗槐的合理施肥和科学管理提供依据。

直播油菜氮磷钾肥料利用率试验探究

近年来,勉县直播油菜得到了突飞猛进的发展,面积已占全县油菜种植面积的80%以上。为准确掌握直播油菜的需肥规律和精准施肥,勉县农业技术推广中心开展了直播油菜肥料利用率试验,通过试验测算得知:勉县直播油菜在推广氮磷钾配方施肥技术的前提下,每生产100kg油菜籽需要吸收纯氮、五氧化二磷、氧化钾分别是5.02 kg、2.57 kg、6.22 kg;氮肥利用率46.5%、磷肥利用率18.9%、钾肥利用率53.1%。