Effect of exchangeable sodium percentage and presubmergence on yield and nutrition of rice under field conditions

Summary The effects of exchangeable sodium percentage (ESP) levels of 82, 72, 65 and 35 and 0, 15 and 30 days of presubmergence (submergence prior to the transplanting of rice) on yield and chemical composition of rice and availability of Fe, Mn, Zn and P in soil were studied factorially in a field experiment. Presubmergence increased rice yields at all ESP levels, the effect being more pronounced at high ESP's. Increasing ESP decreased yields and the contents of Ca, Mg, K, Fe, Mn, Zn and Cu but increased that of P and Na in the crop. Presubmergence enhanced absorption of all the above elements by the crop except P, K, Mg, Zn and Cu in the grain and decreased Na in grain and straw. Growing of rice under submerged conditions also facilitated the improvement of these soils. Effects of submergence and ESP on the availability of Fe, Mn, Zn and P in soil and their role in the nutrition of rice are discussed. The results suggest that 15 to 30 days presubmergence improved rice yields on a calcareous sodic soil of the Indo-Gangetic alluvial plain.     

Availability of iron,manganese, zinc and phosphorus in submerged sodic soil as affected by amendments during the growth period of rice crop

Summary Effect of amendments, gypsum (12.5 tonnes/ha), farmyard manure (30 tonnes/ha), rice husk (30 tonnes/ha) and also no amendment (control) on the availability of native Fe, Mn and P and applied Zn in a highly sodic soil during the growth period of rice crop under submerged conditions was studied in a field experiment. Soil samples were collected at 0, 30, 60 and 90 days of crop growth. Results showed that extractable Fe (1N NH₄OAC pH 3) and Mn (1N NH₄OAC pH 7) increased with submergence upto 60 days of crop growth but thereafter remained either constant or declined slightly. Application of farmyard manure and rice husk resulted in marked improvement of these elements over gypsum and control. Increases in extractable Mn (water soluble plus exchangeable) as a result of submergence and crop growth under different amendments were accompanied by corresponding decreases in easily reducible Mn content of the soil. Application of 40 kg zinc sulphate per hectare to rice crop could substantially raise the available Zn status (DTPA extractable) of the soil in gypsum and farmyard manure treated plots while the increase was only marginal in rice husk and control plots indicating greater fixation of applied Zn. Available P (0.5M NaHCO₃ pH 8.5) behaved quite differently and decreased in the following order with crop growth: gypsum>rice husk>farmyard manure>control.     

Responses of Wheat Yield,Macro- and Micro-Nutrients,and Heavy Metals in Soil and Wheat following the Application of Manure Compost on the North China Plain

The recycling of livestock manure in cropping systems is considered to enhance soil fertility and crop productivity. However, there have been no systematic long-term studies of the effects of manure application on soil and crop macro- and micro-nutrients, heavy metals, and crop yields in China, despite their great importance for sustainable crop production and food safety. Thus, we conducted field experiments in a typical cereal crop production area of the North China Plain to investigate the effects of compost manure application rates on wheat yield, as well as on the macro-/micro-nutrients and heavy metals contents of soil and wheat. We found that compost application increased the soil total N and the available K, Fe, Zn, and Mn concentrations, whereas the available P in soil was not affected, and the available Cu decreased. In general, compost application had no significant effects on the grain yield, biomass, and harvest index of winter wheat. However, during 2012 and 2013, the N concentration decreased by 9% and 18% in straw, and by 16% and 12% in grain, respectively. With compost application, the straw P concentration only increased in 2012 but the grain P generally increased, while the straw K concentration tended to decrease and the grain K concentration increased in 2013. Compost application generally increased the Fe and Zn concentrations in straw and grain, whereas the Cu and Mn concentrations decreased significantly compared with the control. The heavy metal concentrations increased at some compost application rates, but they were still within the safe range. The balances of the macro-and micro-nutrients indicated that the removal of nutrients by wheat was compensated for by the addition of compost, whereas the level of N decreased without the application of compost. The daily intake levels of micronutrients via the consumption of wheat grain were still lower than the recommended levels when sheep manure compost was applied, except for that of Mn.     

Nutrient changes in direct-seeded submerged rice soils with varying nutrio-environments

Summary Nutrient changes in submerged rice soil were studied in soil-water-plant ecosystem in direct-seeded rice crop. Continuous removal of nutrients by the crop resulted in ultimate decrease in the availability of NH₄–N, P, K, Ca, Mg, Mn, Zn and Cu. However, there was a slight increase in Fe availability in soil with increase in period of submergence and crop growth. The data was subjected to statistical function fittings to study the nature of changes. Depending on the R²% values, quadratic type was the best fit for pH, available NH₄–N, K, Mg, Fe, Mn and Cu, whereas logarithmic type was the best fit for available P, Ca and Zn. No response was noticed to the application of P and K. Highest correlation coefficient between grain yield and NH₄–N in soil was obtained at the panicle initiation stage indicating that limiting nitrogen during this period might affect grain yield to the maximum extent compared to tiller initiation and maximum tillering stages.     

From Flooded to Aerobic Conditions in Rice Cultivation: Consequences for Zinc Uptake

Scarcity of water causes a shift from flooded to aerobic conditions for rice production in zinc deficient areas in Northern China. This shift alters soil conditions that affect zinc availability to the crop. This paper concerns the effect of aerobic compared to flooded conditions on crop biomass production, grain yield and zinc content. A field experiment was done with six rice genotypes (Oryza sativa L.) grown on a calcareous soil, both with (23 kg Zn ha⁻¹) and without Zn fertilization. Sampling was conducted at tillering and physiological mature stage. Zn concentration in the shoots was significantly lower at both stages in plants grown in the aerobic field. At maturity, Zn uptake, biomass production, grain yield and Zn-harvest index [grain Zn/(shoot + grain Zn)] were lower under aerobic cultivation. Rice genotypes including aerobic rice and lowland rice differ in degree of response to low Zn supply. A twofold difference was found among aerobic genotypes in grain yield and Zn uptake. Also Zn-harvest index varied significantly. Zn application affected neither grain yield nor grain Zn content, although it significantly improved biomass production in both systems in most genotypes. These results demonstrate that introduction of aerobic rice systems on calcareous soils may increase Zn deficiency problems.     

The reduction in zinc concentration of wheat grain upon increased phosphorus-fertilization and its mitigation by foliar zinc application

Background and aims

Malnutrition resulting from zinc (Zn) and iron (Fe) deficiency has become a global issue. Excessive phosphorus (P) application may aggravate this issue due to the interactions of P and micronutrients in soil crop. Crop grain micronutrients associated with P applications and the increase of grain Zn by Zn fertilization were field-evaluated.

Methods

A field experiment with wheat was conducted to quantify the effect of P applications on grain micronutrient quality during two cropping seasons. The effect of foliar Zn applications on grain Zn quality with varied P applications was tested in 2011.

Results

Phosphorus applications decreased grain Zn concentration by 17–56%, while grain levels of Fe, manganese (Mn) and copper (Cu) either remained the same or increased. Although P applications increased grain yield, they restricted the accumulation of shoot Zn, but enhanced the accumulation of shoot Fe, Cu and especially Mn. In 2011, foliar Zn application restored the grain Zn to levels occurring without P and Zn application, and consequently reduced the grain P/Zn molar ratio by 19–53% than that without Zn application.

Conclusions

Foliar Zn application may be needed to achieve both favorable yield and grain Zn quality of wheat in production areas where soil P is building up.     

Effect of gypsum,pressmud, fulvic acid and zinc sources on yield and zinc uptake by rice crop in a saline-sodic soil

Summary The application of fulvic acid to a saline-sodic soil augmented the solubility of zinc by thousands fold. Zinc fulvate when applied at levels equivalent to that of zinc sulphate was more effective in enhancing diffusion of zinc in the soil. Application of gypsum, zinc sulphate and fulvic acid significantly increased dry matter yield and uptake of zinc by rice crop in a saline-sodic soil. Application of gypsum with pressmud or with fulvic acid and zinc sulphate resulted in significantly higher yield and zinc uptake than in other treatments.     

黔中喀斯特山区村级尺度土壤养分空间变异性及其与水稻产量的关系

以贵州省安顺市西秀区旧州镇文星村为研究区域,采用地统计学方法,研究了黔中喀斯特山区土壤pH值、有机质、碱解氮、有效磷、速效钾、全氮、全磷、全钾、有效铜、有效锌、有效铁、有效锰和水稻产量的空间变异规律及其相互关系.结果表明: 土壤pH值、碱解氮、有效磷、速效钾、全磷、有效铜及水稻产量构成因素的C₀/(C₀+C)<25%,表现为强烈的空间相关性,有机质、全氮、全钾、有效锌、有效铁、有效锰及水稻产量的C₀/(C₀+C)为25%~75%,具有中等空间相关性.土壤速效钾含量与水稻产量关系最为密切,偏相关系数达到极显著水平(r=0.4669,P<0.0001),土壤碱解氮、速效钾和有效磷对有效穗数和千粒重的直接通径系数均为正值,其大小顺序与偏相关分析结果一致.克里金插值结果表明,土壤有机质、碱解氮、速效钾、全氮、有效铜、有效锌的含量在研究区均存在从西南向东北逐渐递减的趋势;产量在西北部及东南部较高.     

Relative effectiveness of various types and methods of zinc application on rice and maize crops grown in calcareous soil

Summary Application of zinc sulphate mixed with compost/poultry manure proved to be equivalent to the effect of dipping the seedling roots in 4% ZnO suspension with respect to rice yields but Zn-amended organic manures were superior to other treatments with regards to total Zn uptake. A marked residual effect of soil applied treatments was recorded on the succeeding maize crop. Application of poultry manure alone was about one and a half times more effective than compost alone in increasing the rice and maize grain yields. Poultry manure surpassed compost in increasing zinc uptake by the crops and at the same time it built up more available Zn in soil than compost for the following crop. The magnitude of yields and Zn uptake response were magnified when zinc sulphate was applied along with organic manures. Application of 25 kg zinc sulphate/ha alone had the same effect as 50 quintals poultry manure alone or 12.5 kg zinc sulphate applied with 50 quintals compost/ha with respect to crop yields. A significant positive correlation was, recorded in both the crops between Zn concentration in grain or straw and their respective yields.     

Effects of short-term flooding on growth,yield and mineral composition of wheat on sodic soil under field conditions

In sodic soils of the Indo-Gangetic alluvial plains of Northern India, flooding for short periods often occurs during the growing season of wheat, leading to low yields. A field study was therefore conducted to evaluate the effects of short-term flooding on growth, yield and mineral composition of wheat (Triticum aestivum Linn. emend. Fiori and Paol) in a sodic soil (pH 8.9, exchangeable sodium percentage 25). Flooding wheat for 2,4 and 6 days at the time of first irrigation (25-day old plants), significantly reduced tillering, plant height, delayed head emergence and resulted in 17.6, 29.0 and 46.7% reduction in grain yield, respectively, Flooding decreased oxygen diffusion rate (ODR) values, restricted root grwoth and reduced ion uptake, especially of N, P, K, Ca, Mg and Zn and led to higher absorption of Na, Fe and Mn. Under the conditions of this experiment, the reduced growth and yield of wheat resulting from short-term flooding was not due to Mn, Fe and Na toxicity but may be due to reduced uptake of nutrients resulting from O₂ deficiency in the soil.     

大庆地区农牧业中微量元素缺乏性营养障碍的土壤根源与整治途径

采集2887个样品分析制图,揭示出大庆地区土壤有效态Cu、Zn、Fe、Mn的含量水平和分布规律,并对该地区不同土壤类型的微量元索含量和有效性做了分析评价,肯定了大多数土壤普遍缺Zn和一定程度上Fe、Mn供给不足,是营养障碍发生的直接土壤因素。从成土母质和成土过程造成的土壤理化性质分析了导致微量元素供给不足的原因;土壤沙化、盐碱化、高pH值、多石灰质和重碳酸盐等起主导作用。提出了改良和培肥土壤、推行合理种植制度、合理施用微量元素肥料及选择栽种耐缺植物种和品种等整治途径。     

Using iron fertilizer to control Cd accumulation in rice plants: A new promising technology

Effects of two kinds of iron fertilizer, FeSO₄ and EDTA·Na₂Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA·Na₂Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA·Na₂Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentration in cereal crop foods in State standard. However, soil application of FeSO₄ or foliar application of FeSO₄ or EDTA·Na₂Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentration of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA·Na₂Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.     

Response of rice to iron-zinc interrelationships in a latiritic soil (oxisol)

Summary Influence of iron-zinc interrelationships on the dry matter yield of rice and total uptake of iron and zinc was studied in a greenhouse experiment on a lateritic soil from Dapoli. Maharashtra. A significant influence of zinc alone was observed on the yield. Iron and zinc either alone or in combination have significantly influenced uptake of Fe and Zn. Highest yield was recorded due to the addition of 10 ppm Fe and 10 ppm Zn at which highest uptake of Zn was noted.     

Build up and depletion of soil phosphorus and potassium and their uptake by rice and wheat in a long-term field experiment

Summary In a field experiment initiated at the Central Soil Salinity Research Institute, Karnal in 1974 involving rice wheat cropping sequence and NPK fertilizer use on sodic soil (pH 9.2, ESP 32.0), an attempt was made to evaluate the available P and K status of the soil and their uptake by the crops during 1982–83 and 83–84.Application of P to either or both the crops significantly enhanced the yields of rice and improved available P status of the soil. Wheat yields remained unaffected. Fertilizer N reduced P content in rice but increased P uptake in crops and considerably brought down available P to a level (4.5 ppm) where rice plants showed reduced tillering and phosphorus deficiency. Application of K did not affect the yield of either crop but enhanced its available status in soil and uptake by the crops. Contribution of the non-exchangeable K towards total potassium removal was about 93% in the absence of applied K which decreased to 87% with the use of K. Application of K to both crops resulted in lesser uptake from non-exchangeable form as compared to its application to either crop. Laboratory studies carried out on soils of the experimental plots showed that cumulative K release measured after five successive extractions was higher in K-treated soils as compared to untreated ones. The major difference was only in the first extraction representing the exchangeable K after which release became independent of the available K of the soil.     

栽培模式对旱地小麦产量和土壤肥力的影响

通过田间试验,研究地膜覆盖、秸秆还田和种植绿肥对冬小麦籽粒产量和土壤肥力的影响.结果表明: 与传统模式相比,地膜覆盖并不总能提高旱地小麦产量,3年平均产量无显著变化,但降低20～40 cm土壤全氮、有效磷、速效钾、有效硫、有效锌和有效锰含量,对土壤有机质、硝态氮、有效铁和有效铜含量无显著影响.秸秆还田的小麦产量3年平均降低12.1%,收获期0～20 cm土层全氮提高5.8%,20～40 cm土层有效铜含量提高6.2%,而有效磷和有效锰分别降低36.1%和10.2%,对开花期和收获期土壤有机质、硝态氮、速效钾、有效硫、有效锌和有效铁无显著影响.种植绿肥的籽粒产量降低12.1%,同时土壤pH、有效磷和有效硫含量降低,有机质、全氮、硝态氮、有效锌和有效锰均增加,对土壤速效钾、有效铁和有效铜均无显著影响.综上,在旱地土壤肥力较低的条件下,地膜覆盖和秸秆还田不利于土壤肥力的提升,使小麦增产受到限制;种植绿肥培肥效果最好,但应考虑区域降水情况,注意其带来的减产问题.     

微量元素硼和锌在作物营养平衡中的作用

许多土壤中B、Zn由于含量或有效性低而供给不足,成为作物营养平衡与大面积产量提高的重要限制因素。采取各种方法直接施用B、Zn,或者配制在尿素中施用,可以调节作物营养平衡,改善作物-环境生态关系,提高产量和品质。在水稻旱育苗地区还可把Zn配在育苗土壤调制剂中施用。在缺Zn褐土上,施入的Zn迅速转化为各种形态,其中碳酸盐结合态是有效Zn的主要仓库。配合施用P肥对Zn的有效性无不良影响,Zn与N、P配合施用有益于作物营养平衡。     

短链聚磷酸磷肥对土壤无机磷转化及铁锰锌有效性的影响

明确聚磷酸形态磷在土壤中的转化及其对土壤磷有效性的影响是聚磷酸类磷肥合理施用的前提.本研究通过盆栽试验比较了施用磷酸一铵和聚磷酸类磷肥对石灰性土壤和酸性红壤有效磷、无机磷转化和土壤微量元素活化的影响,同时研究了不同磷源在油菜上的施用效果.结果表明: 聚磷酸磷肥可显著提高石灰性土壤磷的有效性.与磷酸一铵(MAP)处理相比,聚磷酸处理的土壤水溶性磷和有效磷平均含量分别提高了19.0%和25.4%;对土壤无机磷连续浸提试验表明,Resin-P(树脂磷)和NaHCO₃-P(高活性磷)较MAP处理分别提高了22.8%和43.3%,NaOH-P(中活性磷)较MAP处理提高了33.8%,说明聚磷酸磷肥可显著减少石灰性土壤对磷的固定.在酸性红壤上,施用聚磷酸类磷肥对提高土壤磷的有效性及减少磷的固定效果不明显.聚磷酸磷肥可显著提高石灰性和酸性土壤Fe、Mn、Zn的有效性.与MAP处理相比,聚磷酸肥料处理下石灰性土壤有效Fe、Mn、Zn分别提高了2.1%、16.2%和20.8%,红壤的有效Fe、Mn、Zn含量分别高了6.6%、11.9%和9.2%.聚磷酸磷肥显著提高了石灰性土壤上油菜干物质、吸磷量和磷肥利用率,但在酸性红壤上聚磷酸磷肥处理肥料效应却低于MAP处理.总之,聚磷酸磷肥在提高石灰性土壤中磷的有效性、减少磷的固定、活化Fe、Mn、Zn等微量元素以及改善油菜磷素营养方面均具有显著效果,是在石灰性土壤上能有效替代正磷酸磷肥的新型磷肥.     

Using iron fertilizer to control Cd accumulation in rice plants: A new promising technology

Effects of two kinds of iron fertilizer, FeSO4 and EDTA·Na2Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA·Na2Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA·Na2Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentra- tion in cereal crop foods in State standard. However, soil application of FeSO4 or foliar application of FeSO4 or EDTA·Na2Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentra- tion of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA·Na2Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.     

Application of Zinc,Iron and Boron Enhances Productivity and Grain Biofortification of Mungbean

Deficiencies of essential vitamins, iron (Fe), and zinc (Zn) affect over one-half of the world’s population. A significant progress has been made to control micronutrient deficiencies through supplementation, but new approaches are needed, especially to reach the rural poor. Agronomic biofortification of pulses with Zn, Fe, and boron (B) offers a pragmatic solution to combat hidden hunger instead of food fortification and supplementation. Moreover, it also has positive effects on crop production as well. Therefore, we conducted three separate field experiments for two consecutive years to evaluate the impact of soil and foliar application of the aforementioned nutrients on the yield and seed biofortification of mungbean. Soil application of Zn at 0, 4.125, 8.25, Fe at 0, 2.5, 5.0 and B at 0, 0.55, 1.1 kg ha⁻¹ was done in the first, second and third experiment, respectively. Foliar application in these experiments was done at 0.3% Zn, 0.2% Fe and 0.1% B respectively one week after flowering initiation. Data revealed that soil-applied Zn, Fe and B at 8.25, 5.0 and 1.1 kg ha⁻¹, respectively, enhanced the grain yield of mungbean; however, this increase in yield was statistically similar to that recorded with Zn, Fe and B at 4.125, 2.5 and 0.55 kg ha⁻¹, respectively. Foliar application of these nutrients at flower initiation significantly enhanced the Zn contents by 28% and 31%, Fe contents by 80% and 78%, while B contents by 98% and 116% over control during 2019 and 2020, respectively. It was concluded from the results that soil application of Zn, Fe, and B enhanced the yield performance of mungbean; while significant improvements in seed Zn, Fe, and B contents were recorded with foliar application of these nutrients.     

Transformation and movement of zinc in an alkali soil and their influence on the yield and uptake of zinc by rice and wheat crops

Summary In the summer of 1980, a field experiment was started to evaluate the direct and residual effect of applied zinc (as zinc sulphate) on the yield and chemical composition of rice and wheat grown as crops in sequence, on an alkali soil. The treatments comprised six rates of zinc 0, 2.25, 4.5, 9.0, 18.0 and 27.0 kg ha⁻¹ applied either only once to the first crop, or repeated to each successive crop in a split plot design with 4 replications. Gypsum at 14 t ha⁻¹, was applied uniformly to all plots. The results show that with respect to increase of yield and available zinc content of soil, an application of 2.25 kg ha⁻¹ zinc frequently to each crop was better than a single high dose. A major portion of the applied zinc accumulated in the 0 to 10 cm soil layer; the movement of zinc to lower layers was negligible. Zinc applications increased the concentration of exchangeable < complexed < amorphous sesquixoides-bound zinc > crystalline sesquioxide-bound zinc fractions. Amorphous sesquixoides bound the major portion of the applied zinc compared to other fractions. Exchangeable and amorphous sesquioxide-bound zinc fractions contributed significantly more to zinc uptake by rice, than the other fractions. DTPA extracted zinc more readily from exchangeable and complexed fractions than from sesquioxides. Application of zinc increased the DTPA extractable zinc and hence zinc uptake by plants.