Corn forage yield and chemical composition as influenced by sulfur fertilization

Abstract

Soil sulfur (S) deficiency for plant growth has become an increasing problem in the United States. A field experiment was conducted to investigate effects of fertilization with 0 and 67 kg S/ha as a single or split application, in a Latin square design, on corn (Zea mays L.) forage yield and chemical composition. Sulfur fertilization by either method increased yield of whole plant and grain 7% and increased number of plants with two ears. Total S and sulfate‐S concentration in whole corn plants, leaf, stem, and grain were increased with S fertilization. The nitrogen (N):SO₄‐S ratio was a useful indicator of S deficiency.     

Chloride effects on corn

Abstract

Chloride (Cl) toxicity was suspected in corn (Zea mays L.) growing in a poorly‐drained Atlantic Coast Flatwoods soil where Cl toxicity of soybean {Glycine max (L.) Merr.} was a problem. Field and greenhouse research was conducted with rates of applied Cl in an effort to induce Cl toxicity in corn.

‘Trojan 114’ corn was grown in the greenhouse with Cl rates (KCl) of 0, 364, and 728 ug/g and in the field with rates of 0, 85, 170, and 340 kg/ha. Potassium sulfate (K₂SO₄) treatments were included to supply equivalent amounts of K as that in KCl.

Phytotoxicity of corn did not occur in greenhouse or field experiments with any fertilizer treatment. In the greenhouse Cl concentrations in 26‐day old corn plants grown in a poorly‐drained Flatwoods soil (Leefield sand ‐ arenic Plinthaquic Paleudult) for the 0 and 728 ug Cl/g treatments were 5.0 and 32.7 g/kg in shoots, 1.6 and 14.9 g/kg in ear leaves, and 1.3 and 16.5 g/kg in stalks, respectively. In the field, Cl treatments applied to corn grown in a poorly‐drained Flatwoods soil (Alapaha sand ‐ arenic Plinthic Paleaquults) were not as effective in increasing Cl concentrations in shoots and ear leaves as that for corn grown in a well‐drained soil (Tifton loamy sand ‐ thermic Plinthic Paleudult) apparently because of the greater amount of residual soil Cl in the poorly‐drained soil. Concentrations of Cl in shoots of corn receiving O and 340 kg Cl/ha were 3.8 and 18.0 g Cl/kg, respectively, for corn grown in the well‐drained soil and 16.1 and 18.0 g Cl/kg, respectively, for corn grown in the poorly‐drained soil. Grain yields were not affected by fertilizer treatments on either soil and Cl concentration in grain for corn grown in the Tifton soil was not different among treatments. These data indicate that corn is not very susceptible to high levels of soil Cl.     

压实度对玉米青贮开窖后营养品质及有氧稳定性的影响

为青贮玉米生产实践选择适宜压实度。该研究通过探究不同压实度对玉米(Zea mays L.)青贮营养、发酵品质及有氧稳定性的影响。建立多元线性回归模型为生产实践提供参考。以新饲玉10号青贮玉米为材料,发酵装料密度设计为5个水平(350、400、500、600、700 kg/m~3),发酵期为50 d,检测开窖后各青贮压实度在第0、12、24、36、60、108 h时的营养成分和发酵品质的变化,并用多通道温度记录仪监测温度变化,建立多元线性回归模型。结果表明,350 kg/m~3青贮压实度处理组中干物质(dry matter)和粗蛋白(crude protein)密度相比500、600和700 kg/m~3青贮压实度处理,始终显著降低了2.6%~11.9%和22.8%~37.0%(P0.05);与500、600和700 kg/m~3压实度处理组中的中性洗涤纤维(Neutral detergent fiber)、酸性洗涤纤维(acid detergent fiber)、氨态氮(NH3-N)浓度以及p H值相比,350 kg/m~3青贮压实度处理显著提高了1.2%~4.6%,6.2%~14.1%,14.1%~37.4%和3.1%~39.9%(P0.05)。各指标与开窖时间、压实度和发酵温度间的多元线性回归模型拟合度达到76.8%~92.3%,R2达到0.590~0.853。其中,CP浓度的拟合度和R2最高。因此,增加青贮压实度,可改善开窖后青贮营养、发酵品质,提高有氧稳定性,压实度为600 kg/m~3的玉米青贮发酵品质及有氧稳定性最好,建议600 kg/m~3为全株玉米最佳青贮压实度,对于指导生产实践具有重要意义。     

Effect of lead treatment on the distribution of essential elements in cucumber

Changes in the fresh and dry weight of leaf blades, petioles, internodes, and their ion concentrations as well as rates of root exudation were investigated in cucumber grown in hydroponic culture and treated with physiological concentrations of lead (Pb). The growth of flowering cucumber supplied with FeCl₃ shows a typical bell‐shaped curve derived from leaf dry weights, where the 4th, 5th, and 6th leaves are the largest ones. Lead inhibited growth up to 20% (except the youngest leaves which were stimulated), but did not cause morphological changes. Whereas root growth was also retarded by about 20%, exudation was inhibited to 50%, that is, the root resistance to water transport was increased by Pb. In spite of that the dry matter yield of internodes and petioles hardly reached 10 and 5% of that of leaf blades, respectively, their calcium (Ca), magnesium (Mg), and zinc (Zn) concentrations were almost the same. Similarly, the concentrations of these metals in the specific leaf blades are equal despite their different growth characteristics but the concentration of Mn is independent of the growth of the examined tissues. Lead was the only cation to accumulate in the largest leaves. The inhibitory effect of Pb on ion uptake was proportional to the growth inhibition of the tissues except manganese (Mn), the accumulation of which was stimulated by Pb in all the analyzed tissues and copper (Cu) which increased only in the internodes. We could not explain the extremely different ion distributions observed during the growth of cucumber. However, it is evident that the measurement of ion concentrations at whole shoot level is not enough to characterize ion interactions because only some ions accumulate at the same rate as tissues grow. These ions maintain stable concentration levels in shoot parts whereas others decrease or increase independently from growth.     

Effect of pH on soil magnesium and its absorption by corn

Abstract

Lime induced depression of exchangeable Mg had been observed previously and it was postulated that yield decreases, which frequently occur at high pH levels may in some instances be due to Mg deficiency. This study was conducted to evaluate the influence of pH on exchangeable Mg in a wide range of acid soils and to determine the effects on recovery of Mg by corn (Zea mays L.) in the greenhouse. Treatments consisted of five pH levels, three P levels, and three Mg levels. Soil Mg was extracted with two neutral salt solutions and double acid. Salt extractable Mg decreased markedly at near neutral pH values, but double acid extractable Mg remained essentially unchanged. In several of the soils where yields were depressed at the highest pH levels, plant Mg content was also significantly lower. However, yield depressions were not ameliorated by Mg applications and could not be ascribed to induced Mg deficiency. Decreased plant uptake of Mg at both low and high pH levels was considered to have resulted from competitive effects between Mg and Al. The evidence suggested that salt extractable Mg did not accurately reflect plant availability.

Because soil reaction has profound effects on the availability of aluminum and many elements essential to plants, liming should be practiced primarily to optimize the utilization of the nutrient resources of soil. While pH values near neutrality are regarded as optimal in many areas of the world, particularly where legumes have traditionally been part of the rotational system, yield depressions have sometimes been reported at such pH levels on highly weathered acid soils of tropical and subtropical origin.     

Container and Installation Time Effects on Soil Moisture,Temperature, and Inorganic Nitrogen Retention for an in situ Nitrogen Mineralization Method

Mineralization contributes significantly to agronomic nitrogen (N) budgets and is difficult to accurately predict. Models for predicting N‐mineralization contributions are needed, and development of these models will require field‐based data. In situ mineralization methods are intended to quantify N mineralization under ambient environmental conditions. This study was conducted to compare soil moisture and temperature in intact soil cores contained in cylinders to those in adjacent bulk soil, compare the effect of two resin‐bag techniques on water content of soil within cylinders, and assess the effect of installation duration on inorganic N retention by resins. The study was conducted at a dryland conventionally tilled corn (Zea mays L.) site and an irrigated no‐tillage corn site in eastern Nebraska. Soil in cylinders was slightly wetter (<0.05 g g^?1) and warmer (<1 °C) than adjacent soil. Soil water content was <80% water‐filled pore space (WFPS) at all sampling times and differed little between the two resin‐bag techniques. Greater soil water content and temperature conditions (though small) observed during most of the study period likely enhanced N mineralization within the cylinder compared to N mineralization in adjacent bulk soil, but the magnitude is likely much less than core‐to‐core variation normally observed in a field. Installing cylinders for more than 60 days resulted in loss of inorganic N from resins. Care is needed during installation to ensure that compaction of soil below the cylinder does not impede water movement through the intact soil core. The in situ method utilizing intact soil cores and resin bags replaced at 28‐ to 40‐day intervals is a viable method for measuring N mineralization.     

EFFECT OF NITROGEN SOURCES AND RATES ON YIELD AND QUALITY OF SILAGE CORN

The objective of this study was to determine the effect of nitrogen (N) application source and rate on silage corn (Zea mays L.). Urea, ammonium nitrate, and ammonium sulfate were compared at 50, 100, 150, and 200 kg N ha^?1. The application of ammonium sulfate produced the highest plant height, leaf area index (LAI), total yield, and stem, leaf, and ear dry matter, followed by ammonium nitrate and urea. However, nitrogen sources had no marked effects on the content of protein, ash, oil, soluble carbohydrates, acid detergent fiber (ADF) and neutral detergent fiber (NDF). As the rate of nitrogen increased plant height, LAI, total yield, and stem, leaf, tassel, and ear dry matters, and protein, ash and oil contents increased while soluble carbohydrates, ADF, and NDF contents decreased. Ammonium sulfate was the most effective N source on production and 200 kg N ha^?1 was the most effective N rate on corn yield and quality.     

Effect of population size and yield level in selection of diagnosis and recommendation integrated system (DRIS) norms

Abstract

A data bank comprising over 8000 observations of yield and tissue composition was assembled from a wide range of locations and conditions. DRIS norms were developed from parts of the data bank representing different sources and chronology in its development. The effects of population size and yield level used to discriminate between high and low yielding subpopulations on the DRIS norms are studied. The results indicate that the best banks are those which are large, random and have a substantial number of high yield observations.     

氮素营养对黄土高原旱地玉米产量、品质及水分利用效率的影响

20022003年在陇东旱塬的甘肃省农科院镇原旱农试验基地秋覆膜玉米地上进行了不同施氮量对旱地玉米产量、品质及水分利用效率影响试验。结果表明,不同年份氮肥用量对不同类型玉米品种产量均有极显著差异,但同一年份不同类型玉米品种或不同年份同一类型玉米品种产量无显著性差异。玉米产量随着施氮量的增加而提高,且每公斤氮肥增产量、水分利用效率(WUE)、光合速率(Pn)等均以中氮(N.180.kg/hm2)时最大。在中等氮肥水平以下,玉米子粒粗脂肪、粗蛋白和淀粉含量随施氮量的增加而提高,同时,歉水年份有利于容重、粗蛋白和淀粉的累积。     

The nitrogen content of corn grain as affected by hybrid,population, and location

Abstract

Samples were taken from 9 of the 20 major experiments which comprised the Illinois commercial corn (Zea mays L.) performance trial and evaluated for grain yield, percent grain N, and grain N yield.

The mean percent N in the grain was 1.54%, with 91.8% of the samples between 1.34 to 1.74%. Although location and plant population affected the mean values, the range of values about the mean was relatively unaffected. Grain N yield was more closely correlated with grain yield than with percent grain N.     

Silage yield and quality of row intercropped maize and soybean in a crop rotation following winter wheat

Maize (Zea mays L.) intercropped with soybean (Glycine max L.) may be a viable option to improve the quality of the silage. In this study, maize and soybean intercropped in different numbers of rows and their monocropping equivalents were tested to determine the best intercropping system in a crop rotation following winter wheat. The treatments were monoculture maize (M), monoculture soybean (S), 75% maize + 25% soybean (3M:1S), 50% maize + 50% soybean (2M:2S) and 25% maize + 75% soybean (1M:3S). The experiment was laid out in a randomized complete block design with three replications in 2011 and 2012 in Antalya, Turkey. Highest fresh forage yields were obtained from maize (53.3 t ha^?1) and 3M:1S (62.8 t ha^?1) treatments in 2011 and 2012, respectively. Maize treatment had highest dry matter yield (21.1 and 22.0 t ha^?1) in both years. Quality analysis of silage revealed that 3M:1S was superior to maize treatment in terms of dry matter (25.23%), crude protein (7.31%), crude fiber (18.27%), neutral detergent fiber (42.56%), acid detergent fiber (25.81%), lactic acid (4.71%) and acetic acid (4.05%). In conclusion, 3M:1S row intercropped production system was a better alternative for silage to monoculture maize in a crop rotation following winter wheat.     

不同钾肥施用量对玉米抗倒性能及产量的影响

以先玉335和郑单958为试验材料,针对不同钾肥施用量(0、50、100、150、200kg/hm~2)对玉米茎秆形态特征、干物质积累特性及产量的影响进行系统研究。结果表明:随着钾肥用量的增加,两品种穗位高系数均呈"V"型曲线,在K2处理(100kg/hm~2)时最低。与郑单958相比,先玉335第3~6节的节间长/节间直径对钾肥施用量的变化更敏感,呈现增加-降低-增加的变化规律。同一钾肥处理同一节位,郑单958节间长和节间长/节间直径均小于先玉335。钾肥用量对节间直径无显著影响。两个品种节间干物质比、单位节间干重和茎秆强度均随钾肥用量的增加先升高后降低。相关分析表明:玉米茎秆强度与单位节间干重呈极显著正相关。适宜的钾肥施用量对产量有一定的正效应,本试验5个处理中,钾肥施用量为100kg/hm~2时两玉米品种产量最高。     

不同添加剂对全株玉米和青玉米秸青贮饲料质量的影响

为了探讨不同添加剂对全株玉米和青玉米秸青贮饲料质量的影响,利用乳酸菌制剂和酶制剂单独或联合使用对原料进行青贮调制，并对开封后的青贮饲料进行了现场评定、实验室评定、生物评定和二次发酵试验。结果表明：不同添加剂处理后得到的全株玉米、青玉米秸青贮饲料的感官评定均优于对照组；在降低青贮饲料的NDF、ADF含量，提高动物的消化率上，乳酸菌制剂和酶制剂混合作用时的效果最显著；另外，乳酸菌1和乳酸菌1＋酶制剂1能够有效地抑制青贮饲料的二次发酵。     

Responses of photosynthesis,chlorophyll fluorescence,and grain yield of maize to controlled‐release urea and irrigation after anthesis

Controlled‐release urea (CRU) is a new type of urea, which may increase crop nitrogen (N)‐use efficiency compared with conventional urea (CU), but the conditions where it outperforms urea are not well defined. A field experiment assessing responses of plant growth and grain yield of maize to CRU and irrigation was conducted on a typical agricultural farm in Shandong, China. Five treatments of the two types of urea (75, 150 kg N ha^–1, 0 kg N ha^–1) were applied as basal fertilizer when sowing maize, and two water treatments (W₀ and W₁) were used 23 d after anthesis. Net photosynthetic rate (P_N) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU‐treated plants than in CU‐treated plants at grain filling and maturing stages. CRU significantly enhanced the maximum photochemical efficiency (F_v / F_m), PSII coefficient of photochemical fluorescence quenching (q_P), and actual quantum yield of PSII electron transformation (Φ_PSII) but decreased the nonphotochemical quenching (NPQ). Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis. Significant positive correlations were found between cob‐leaf N concentration and P_N both with and without irrigation. Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions. In conclusion, CRU as a basal application appeared to increase the N‐use efficiency for maize relative to CU especially by maintaining N supply after anthesis.     

Influence of sulfur deficiency on chlorophyll‐meter readings of corn leaves

Sulfur (S)‐diagnostic tools are essential for rational use of S fertilizers. There is little information about the suitability of leaf greenness intensity to detect S deficiency in corn (Zea mays L.). This work evaluates, under controlled S‐stressed conditions, (1) the performance of leaf greenness intensity as an indicator of the degree of S deficiency in corn, and (2) the advantage of the upper leaves in relation to the middle leaves for S‐deficiency determination. A pot experiment using sand as growth medium was conducted in greenhouse with corn at S rates of 0, 5, 10, 20, and 40 mg kg^–1 and sufficiency of other nutrients. Measurements of aboveground biomass (AB), total nitrogen (N), and S concentrations, and chlorophyll‐meter readings (CMR) in upper and middle leaves, were performed at the growth stages of 6–7, 11–12, and 14–15 fully expanded leaves (V6‐V7, V11‐V12, and V14‐V15, respectively). Sulfur application significantly increased AB, leaf S concentration, and CMR. Significantly positive relationships were obtained between leaf S concentration and CMR. A sulfur‐sufficiency index (SSI) based on CMR measured in upper and middle leaves was significantly associated with AB (R² = 0.58 and 0.62 for the middle and upper leaves, respectively). It is concluded that under sufficiency of other nutrients and high‐S‐stressed conditions, leaf greenness intensity could be a good indicator of corn S status, although little or no advantage was found for taking CMR from the upper leaves.     

Response of corn to NPK fertilization grown in a Latosol in South Sulawesi,Indonesia

Abstract

Corn (Zea mays L.) is next to rice as an important food crop grown in South Sulawesi, Indonesia. However, yields obtained by farmers are rather low, around 0.6 to 1.0 ton/ha. Efforts to increase yield have been tried through the application of NPK fertilizers. A study was conducted to determine the effects of N, P and K application on corn yield and what soil constrains, in terms of nutrient elements in the corn plants, exist in the latsols found at Desa Tokka, Sinjai, and South Sulawesi. It was found that application of K significantly increased the growth and corn grain yields on the latosols at Sinjai. Without K, grain yield and the K content in the ear leaf were low. The correlation between grain yield and rate of K shows that an application of 72 kg K₂O/ha together with 90 kg N and 80 kg P₂O₅ per ha produce the best yield of 3.6 tons/ha. The K content in the ear leaf of 1.8% was related to this maximum yield.     

季节性干旱条件下氮肥与密度运筹对鲜食糯玉米产量的影响

为探讨季节性干旱下糯玉米的高产栽培模式,本试验研究了氮肥和密度运筹下糯玉米的产量与氮肥农学利用率.结果表明,在9至11月的干旱条件下,随着密度和施氮量的增加,鲜果穗产量逐渐增加,在氮肥用量(225 kg/hm2)和6万株/hm2处理下玉米鲜果穗产量最高,比不施氮处理提高了32.29％.氮农学效率表现较高的为中施氮量(175 kg/hm2)、中密度(5.25万株/hm2)和中施氮量(175 kg/hm2)、高密度(6万株/hm2)处理,分别为10.57 kg/kg和11.79 kg/kg,表现最低的为高施氮量(275 kg/hm2)、低密度(4.5万株/hm2),为3.76 kg/kg.因此,在南方红壤地区,通过合理搭配氮肥量和种植密度,可以在季节性干旱下实现鲜食糯玉米的高产.     

施钾对高油玉米和普通玉米吸钾特性及子粒产量和品质的影响

采用田间试验研究钾肥用量对高油玉米和普通玉米吸钾特性及子粒品质和产量的影响。结果表明,两品种钾素吸收最大速率随施钾量的增加呈增加趋势,在施K2O.90150.kg/hm2范围内,通油1号的钾素吸收最大速率大于四密25。成熟期通油1号的吸钾总量明显高于四密25,但其子粒产量却低于四密25。玉米子粒的钾素绝大部分来源于开花后根系的吸收。通油1号开花后根系钾素吸收量和成熟期子粒钾素吸收总量明显高于四密25。高油玉米通油1号含有较高的脂肪酸和蛋白质含量,但淀粉含量较低。施钾在提高产量的同时,增加了子粒中脂肪和蛋白质及其组分含量,但减少了淀粉总量和支链淀粉含量。表明子粒中淀粉、蛋白质、脂肪和产量之间存在内在联系。     

Yield,Quality Components,and Nitrogen Levels of Silage Corn Fertilized with Urea and Zeolite

The zeolite and urea mixture may be use to improve nitrogen (N)–use efficiency of silage corn. The objective of this study was to evaluate dry-matter yield and nutritional levels of N of silage corn fertilized with urea and zeolite mixture. The experimental design was a 2 × 4 × 4 factorial randomized block design with three replications. Treatments included two types of stilbite zeolite (natural and concentrated), four levels of nitrogen (0, 50, 100, and 200 kg ha^?1), and four ratios of zeolite (25%, 50%, and 100% of N level). Treatments were applied 60 days after planting with the topdressing fertilization. The use of concentrated (650 g kg^?1 of stilbite) or natural (470 g kg^?1 of stilbite) zeolite with urea increased silage corn dry-matter production and leaf N concentrations.