不同水稻品种对钾的吸收及其对钾肥的反应

测定了９个水稻品种在０．１ｍｍｏｌ／ＬＫ２ＳＯ４＋０．２ｍｍｏｌ／ＬＣａＳＯ４溶液中吸收２小时和４小时的Ｋ＾＋浓度和ＰＨ值的变化。结果表明溶液的ＰＨ变化与Ｋ＾＋浓度变化呈极显著的正相关，这为建立快速简便地筛选高吸钾速率水稻品种的方法提供了基础。幼苗耗竭试验表明，水稻利用土壤中的钾大部分来自非交换性钾源。各品种的吸钾总量与来自非交换性钾及１ｍｏｌ／ＬＨＮＯ３不能撮的钾和矿物钾均有极显著的相关性，这可     

水稻耐低钾基因型筛选方法的研究

本试验用１／４强度的ＫｉｍｕｒａＢ营养液将灿稻、稻和籼型杂交稻各１１份，分别培养到三叶期后，以含有０．２６５μｍｏｌ／ＬＨ２Ｏ２，０．２ｍｍｏｌ／ＬＣａＳＯ４加０．１或０．２或０．３或０．４ｍｍｏｌ／ＬＫ＾＋的营养液为测定介质，在２５±２℃，连续自然光下，运用离子耗竭技术分别测定了各种不同钾浓度下灿稻、粳稻和杂交稻不同基因型的吸钾速率。并于三叶期和五叶期分别测定这三类基因型的生物量和钾素利用效率。     

应用离子交换树脂膜测定土壤钾素有效性的研究

用国产离子交换树脂膜室内埋置法提取测定了我国北方２４种土壤的速效钾含量。结果表明,用阳离子交换树脂膜提取的土壤钾与用１ｍｏｌ／Ｌ中性ＮＨ４ＯＡｃ及土壤养分综合系统评价方法提取的钾（ＡＳＩ－Ｋ）分别呈显著和极显著的正相关;与盆栽试验不施钾处理玉米幼苗吸钾量呈极显著的正相关,明显高于常用的１ｍｏｌ／Ｌ中性ＮＨ４ＯＡ提取钾与锱某试验玉米幼苗吸钾量之间的相关性。说明可以用国产离子交换树脂膜较好地评价北方土     

籽粒苋富钾基因型筛选研究

在营养液培养或土壤培养条件下,采用植株含钾量、单株吸钾量和植株吸钾率等作为富钾基因型的筛选指标,对不同籽粒苋(红苋Amranthus crenentus)品种的富钾能力进行了筛选。结果表明,D8-1、R109、R104和K12等品种对钾具有较强的富集能力,在低钾溶液培养30d(不包括25d的育苗期)和缺钾土壤培养60d时,其植株含钾(K)量一般都在3%～4%之间,单株吸钾(K)量分别在50～75mg和100～120mg范围内,植株(鲜根)吸钾速率大于1 70mol (gh),为富钾基因型;而M9和Cr047等品种对钾的富集能力则相对较弱,其植株含钾量一般在2.7%以下,单株吸钾量低于40mg和80mg,植株(鲜根)吸钾速率小于1.35mol (gh),属一般型。在供钾正常(K5mmol L,)时,所有品种的含钾量和吸钾量均大幅上升,但随着培养介质中钾浓度的提高,两基因型的富钾能力差距逐渐缩小,低钾溶液培养时含钾量和吸钾量最高的品种分别是最低时的2 5倍和2 3倍,而供钾正常时含钾量和吸钾量最高的品种仅分别为最低的1.3倍和1.8倍。因此,在缺钾土壤上播后60d或0.5mmol L的低钾溶液培养30d,能较好地反映两种基因型在富钾能力上的差异。同时,两种基因型在缺钾土壤上的根冠比和主根长仅为低钾溶液培养时的一半左右。但无论在那种介质中,富钾型的根冠比和主根长均大于一般型;在供钾     

水稻耐低钾基因型的筛选及吸钾特性的研究

筛选水稻耐低钾基因型最直接、客观方法是在低钾土壤上进行田间实验直接筛选,其结果可作为其他方法的比较标准.但该方法需时较长、工作量大,不能满足大批量快速、高速筛选的要求.因此,近年来国内外许多学者在探索用液培的方法进行筛选[1,2].     

蕺菜属植物富钾基因型的筛选

在低钾土壤培养和营养液培养的条件下,采用植株含钾量、吸钾速率和钾素利用率并结合植株根系形态特征,对蕺菜属(Houttuynia Thunb.)16份不同基因型材料的富钾能力进行筛选.结果表明,峨眉蕺菜W01-86以及蕺菜W01-34和W01-71在低钾土壤培养和溶液培养时植株含钾量分别高于9.0%,5.50%,吸钾速率大于1.50μmol/(g·h).低钾土壤培养和溶液培养时的钾素利用率分别高于2.50,0.30g/g,为富钾基因型;W01-4和W01-99低钾土壤培养和溶液培养时的植株含钾量分别低于8.5%,5.0%,吸钾速率小于0.65μmol/(g·h),低钾土壤培养和溶液培养时的钾素利用率分别低于2.00,0.30 g/g,为低钾基因型.     

不同玉米基因型吸钾能力的比较研究

通过耗竭试验采用供钾水平极低的沙土对不同基因型玉米吸钾能力进行了研究。结果表明,不同基因型玉米吸钾量的多少有显著差异,不同基因型玉米吸收土壤中各形态钾素的比例不同。供试品种中农大86的吸钾量和吸收土壤矿物钾的比例显著大于其它品种。不同玉米基因型其吸钾量的多少、吸收土壤矿物钾的多少和比例是判定其吸钾能力强弱的重要指标。     

耗竭条件下冬小麦的吸钾特点及其对土壤不同形态钾的利用

在耗竭条件下研究了冬小麦在我国11种主要土壤上的吸钾特点及其对不同形态钾利用。结果表明,冬小麦对钾的吸收具有明显的阶段性。拔节至齐穗期为吸钾高峰,成熟后出现排钾现象。耗竭条件下冬小麦各生育期土壤交换性钾含量变化不大,而缓效性钾从开穗后开始回升。冬小麦吸收的钾中,交换性钾占的比例较小,11种土壤平均为21.5％;1mol／LHNO3不能提取的钾占绝大部分,平均为78.5％。表明土壤经耗竭后,1mol／LHNO3不能提取的钟对作物钾营养的作用较大。耗竭后土壤交换性钾最低值出现的时期及数量大小是土壤重要的供钾特性之一。     

籼稻不同基因型对钾、钠的反应

本研究用微区试验研究了4种典型基因型在田间条件下对钾、钠反应的遗传差异。这4种基因型是经液培方法从近300种基因型中筛选得到的。结果表明,在低钾条件下,钾高效基因型的钾素利用效率、钾素经济利用效率、对胡麻斑病的抗性等都显著高于钾低效基因型;不同基因型对钠的反应差异明显;茎叶的钾钠含量互成显著的反相关。     

烤烟钾素营养特性的基因型差异研究

以10个烤烟基因型为材料,进行了离子耗竭溶液培养、土壤耗竭盆栽试验和田间小区试验,研究比较钾素营养特性的基因型差异。结果表明,不同基因型的吸钾速率和耐低钾能力差异显著。吸钾速率以红大和K358最大,耐低钾能力Nc27NF和K358最强,Nc729最弱。10个基因型全株含钾量在低钾水平下变幅为0.87%～1.25%,而在高钾水平下为1.40%～1.94%。高钾条件下,基因型G28、77089-12、Rg11和Nc82的叶片含钾量高于2%;K358、Coker319、K346和Nc27NF有较高的钾素利用效率,K346、Nc729、G28和K358的钾素收获指数大于50%。各烤烟基因型的钾素营养特性在不同供钾条件下无显著相关性。综合比较K346属于钾高效基因型。     

Potassium‐fertilizer management in winter oilseed‐rape production in China

Optimal potassium (K) fertilization is beneficial for oilseed‐rape (Brassica napus L.) yield and quality. However, the discrepancy between the high K demand of winter oilseed rape and low soil fertility and insufficient potassium input has limited the sustainable development of oilseed‐rape production. A series of on‐farm experiments in the key winter oilseed‐rape domains of China was conducted from 2004 to 2010 to evaluate K‐fertilizer management for winter oilseed rape. Currently, the average NH₄OAc‐extractable K content in the 0–20 cm soil layer is 89.1 mg kg^–1 indicative of “slight deficiency”. In addition, farmers in China usually fail to use sufficient K fertilizer in oilseed‐rape production, the average mineral‐potassium‐fertilizer input in 2010 being only 35 kg K ha^–1, far lower than the recommended rate of potassium for winter oilseed rape. Adequate potassium fertilization significantly raises seed yield. The average yield‐increase rate for the major production regions due to K‐fertilizer application was 18.5%, and the average K fertilizer–use efficiency 36.1%. Based on the negative correlation between yield response to potassium fertilization and available soil K content, a soil‐K‐test index was established for winter oilseed rape with a threshold value for NH₄OAc‐extractable soil K of 135 mg kg^–1. When available soil K‐content is below this threshold value, more K fertilizer should be applied to achieve high seed yield and to increase soil fertility. The major challenge for K‐fertilizer management in winter oilseed‐rape production in China will be to guide farmers in the different regions in making reasonable use of K fertilizer through soil K‐testing technology in order to maintain both seed yield and soil fertility.     

Potassium distribution in root and non‐root zones of two cotton genotypes and its accumulation in their organs as affected by drought and potassium stress conditions

A rhizobox experiment was conducted to compare the differences of soil potassium (K) distribution and absorption between two cotton (Gossypium hirsutum L.) genotypes under drought and K‐deficit conditions. Treatments included two levels of water (drought and optimum soil moisture: 25% and 35% volumetric water content) and K fertilizer rates (0 and 0.48 g potash kg^?1 soil) applied to two cotton genotypes (namely HEG and LEG). Both the genotypes showed significant differences in total K accumulation without exogenous K addition. After absorption, soil content of the readily available potassium (RAK) decreased rapidly. This promoted the conversion of the mineral K into slowly available potassium (SAK). Drought significantly decreased the cotton growth and K use efficiency, and thereby reduced the effect of K fertilizer. Consequantly, the contents of RAK and SAK were greatly increased. However, K bioavailability was decreased under water stress conditions. Differences in root parameters and soil microorganisms between two cotton genotypes were significantly increased and had marked relations with available soil K contents. This study provides important information for understanding the mechanism of K use efficiency, especially under water and K stress.     

Effect of the application of polluted wheat (Triticum aestivum L. Thell.) straw during plowing on the transfer of radiocesium from the soil to komatsuna (Brassica rapa L. var. perviridis)

Radioactive substances were released into the environment after the nuclear accident at the Fukushima Daiichi Nuclear Power Station; this led to the contamination of the soil at Fukushima Prefecture. Mixing of organic matter with soil during plowing is known to influence radiocesium (¹³⁴Cs and ¹³⁷Cs) absorption by crops. However, the effect of mixing organic matter polluted by radioactive substances during plowing on radiocesium absorption by plants is not yet known. The aim of this study was to investigate the effect on the radiocesium absorption by komatsuna (Brassica rapa L. var. perviridis) cultivated in a 45-L container containing Andosol (14,300 Bq kg^?1) or Gray Lowland soil (33,500 Bq kg^?1) mixed with polluted wheat (Triticum aestivum L. Thell.) straw (2080 Bq kg^?1). The radiocesium concentration of the plants and the soil and the amount of exchangeable radiocesium in the soil were determined using a germanium semiconductor. The transfer of radiocesium from the soil to plants decreased by 53 and 27% in Andosol and Gray Lowland soil, respectively, after the application of 10 t ha^?1 polluted wheat straw. This reduction in the level of radiocesium transfer might be attributed to potassium contained in the wheat straw, which might compete with cesium during membrane transport and thereby block the transport of cesium from the soil solution to the roots and from the roots to the shoots. Alternatively, the applied wheat straw probably absorbed radiocesium and decreased the amount of exchangeable radiocesium in the soil. Our findings suggest that the mixing of polluted wheat straw with contaminated soil might influence the absorption of radiocesium content by agricultural products. Further studies are warranted to determine the long-term effects of the application of polluted wheat straw on the rate of radiocesium transfer to crops.     

Mid-Season Prediction of Wheat-Grain Yield Potential Using Plant,Soil, and Sensor Measurements

ABSTRACT

The components that define cereal-grain yield potential have not been well defined. The objective of this study was to collect many differing biological measurements from a long-term winter wheat (Triticum aestivum L.) study in an attempt to better define yield potential. Four treatments were sampled that annually received 0, 45, 90, and 135 kg N ha^?1 at fixed rates of phosphorus (P) (30 kg ha^?1) and potassium (K) (37 kg ha^?1). Mid-season measurements of leaf color, chlorophyll, normalized difference vegetative index (NDVI), plant height, canopy temperature, tiller density, plant density, soil moisture, soil NH₄-N, NO₃-N, organic carbon (C), total nitrogen (N), pH, and N mineralization potential were collected. In addition, soil texture and bulk density were determined to characterize each plot. Correlations and multiple linear-regression analyses were used to determine those variables that can predict final winter wheat grain yield. Both the correlation and regression analyses suggested mid-season NDVI, chlorophyll content, plant height, and total N uptake to be good predictors of final winter wheat grain yield.     

Effect of zinc application methods on apparent utilization efficiency of zinc and potassium fertilizers under rice-wheat rotation

Apparent utilization of zinc (Zn) and potassium (K) fertilizers was examined in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) using combinations of no K; soil applied K levels and no Zn; soil and foliar applied Zn. Application of 33.2 kg K ha^?1 in rice and 24.9 kg K ha^?1 in wheat along with foliar spray of 2 kg Zn ha^?1 at 30 and 60 days gave the highest mean grain yields. Foliar application of zinc increased Zn concentration in flag leaves, grain, and straw of rice and wheat and K concentration in flag leaves of rice and straw of wheat significantly. Potassium application increased Zn concentration in rice grain and straw and K concentration in wheat straw significantly. Zinc and K increased the uptake of each other in grain; straw and total uptake by both crops significantly. Zinc fertilizer enhanced the utilization of soil K. Potassium fertilizer enhanced the utilization of applied Zn.     

The effect of potassium and humic acid applications on yield and nutrient contents of wheat (Triticum aestivum L. var. Delfii) with same soil properties

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   

The effects of straw return on potassium fertilization rate and time in the rice–wheat rotation

In order to investigate the effects of straw return on potassium (K) fertilizer application rate and time in the rice–wheat rotation, field experiments were conducted at three sites. The results showed that when the K rate was decreased to 70% of the recommended K dosage, crop yields showed no significant decrease. With K fertilization only at rice phase, crop yields showed no marked difference compared with that provided K fertilizer both at wheat and rice seasons. Though the NH₄OAc-extracted K and HNO₃-extracted K differed slightly among the treatments, the soil apparent K balance was negative without K fertilization. With crop straw fully incorporated, the recommended K dosage could be at least reduced by 30% at the experimental sites and the K fertilizer could be applied only at rice phase. A further hypothesis can be made that the best K rate was the amount of K took away by crop grain. In the long run, straw return combined with K fertilization would be an effective method to maintain soil K fertility and productivity.     

Phosphorus Influx and Root‐Shoot Relations as Indicators of Phosphorus Efficiency of Different Crops

Abstract

The large variation in phosphorus acquisition efficiency of different crops provides opportunities for screening crop species that perform well on low phosphorus (P) soil. To explain the differences in P efficiency of winter maize (Zea mays L.), wheat (Triticum aestivum L.), and chickpea (Cicer arietinum L.), a green house pot experiment was conducted by using P‐deficient Typic ustochrept loamy sand soil (0.5 M NaHCO₃‐extractable P 4.9 mg kg^?1, pH 7.5, and organic carbon 2.7 g kg^?1) treated with 0, 30, and 60 mg P kg^?1 soil. Under P deficiency conditions, winter maize produced 76% of its maximum shoot dry weight (SDW) with 0.2% P in shoot, whereas chickpea and wheat produced about 30% of their maximum SDW with more than 0.25% P in shoot. Root length (RL) of winter maize, wheat, and chickpea were 83, 48, and 19% of their maximum RL, respectively. Considering relative shoot yield as a measure of efficiency, winter maize was more P efficient than wheat and chickpea. Winter maize had lower RL/SDW ratio than that of wheat, but it was more P efficient because it could maintain 2.2 times higher P influx even under P deficiency conditions. In addition, winter maize had low internal P requirement and 3.3 times higher shoot demand (i.e., higher amount of shoot produced per cm of root per second). Even though chickpea had 1.2 times higher P influx than winter maize, it was less P efficient because of few roots (i.e., less RL per unit SDW). Nutrient uptake model (NST 3.0) calculations satisfactorily predicted P influxes by all the three crops under sufficient P supply conditions (C_Li 48 µM), and the calculated values of P influx were 81–99% of the measured values. However, in no‐P treatment (C_Li 3.9 µM), under prediction of measured P influx indicated the importance of root exudates and/or mycorrhizae that increase P solubility in the rhizosphere. Sensitivity analysis showed that in low P soils, the initial soil solution P concentration (C_Li) was the most sensitive factor controlling P influx in all the three crops.     

施用钾肥对叶菜产量和品质的影响

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.     

Yield formation of five crop species under water shortage and differential potassium supply

A long‐term field experiment on a Haplic Phaeozem, established 1949 with four levels of potassium (K) supply (5, 69, 133, and 261 kg K ha^?1), was analyzed for the interaction between K supply and yield loss of five crop species by water shortage. The crop species were cultivated simultaneously side‐by‐side in the following rotation: potato (Solanum tuberosum L.), silage maize (Zea mays L.), spring wheat (Triticum aestivum L.), beet (Beta vulgaris L.), and spring barley (Hordeum vulgare L.). The treatment with 133 kg K ha^?1 supply had a nearly balanced K budget. In the treatments with lower supply, the soil delivered K from its mineral constituents. On the low‐K plots (especially on those with only 5 kg K ha^?1), crops suffered yield depressions of nearly all main harvest products (cereal grains, potato tubers, beet storage roots, silage maize) and by‐products (straw, beet leaves) by up to 40.7% of dry matter. Only wheat grains were an exception. Potassium concentrations in the harvested plant parts decreased nearly in parallel to the reduction of their dry matter yields, with the exception of cereal grains, which kept stable concentrations even in the treatment with only 5 kg K ha^?1. A comparison of four year‐pairs with differing levels of precipitation in yield‐relevant periods showed an average water shortage‐induced depression of dry matter yields by 19.7% in the main harvest products. The severity of this yield depression was not mitigated by elevated K supply, with the exception of beet leaves, where the dry matter production was stabilized by high K supply. In this crop, the reduction of storage‐root yield was associated with a decrease in harvest index and was therefore obviously caused by an inhibition of assimilate translocation from the leaves into these organs, in contrast to cereals, where water shortage primarily affected dry matter production in vegetative organs. It is concluded that the physiological causes of yield reduction by drought stress and the possibility of its amelioration by K supply differ between plant species and organs.