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1.
Abstract

The aim of this study was to determine the relationships between soil water and nitrogen fertilizer and their effect on grain corn yield (Zea mays L.) in a zone where the limiting factor of yield and nitrogen efficiency is the water supply. The experiments were carried out for 10 years on a deep‐permeable well—drained chernozem in a temperate—continental dry climate with annual precipitation of about 500 mm.

Different nitrogen rates were applied and plant available soil water (PAW) was determined every year before and during the growing season. Multiple regressions were fitted for nitrogen rate, soil water and corn yield.

The results show that there is a significant interaction between soil water content, applied nitrogen and corn yield. The soil water explains the greatest part of yield variation, followed by the soil water‐added nitrogen interaction effect and the direct effect of added nitrogen. The PAH on July 1st gave a better correlation (R2 = 0.88) than June 1st (R2 = 0.85) or March 1st PAW (R2 = 0.72). But the best correlation was obtained when both June and July PAW were taken together in the regression (R2 = 0.914). July PAW was also more efficient in terms of yield per PAW. Thus, 1 mm of PAW on March, June and July 1st increased the control yield by 12.5, 14.6, and 18.3 kg grain/ha respectively, and by 18.0, 22.0 and 32.0 kg grain/ha for the fertilized yield (with 60 kg N/ha). At low soil moisture content, the applied N had no or even negative effect on water use efficiency and yield while at high PAW the water use efficiency was greatly increased by the applied N.  相似文献   

2.
Abstract

The objective of this work was to study the effect of plant available soil water (PAW) in different soil layers before and during the growing season on corn yields (Zea mays L.) and to determine if the soil water may be a reliable index in forecasting the grain yield. The experiments were carried out for 10 years at the same site on a deep‐permeable well‐drained chernozem with good physico‐chemical and biological properties situated in a temperate‐continental dry climate with annual precipitation of about 500 mm and wide seasonal and annual fluctuation.

The results show that the maximum yields (MY) were highly correlated to water stored in the soil as well at the beginning as during the growing season. In most cases the yields were better correlated to PAW at the beginning of June (r = 0.96**) than at the beginning of March (r = 0.87**) or July (r = 0.91**). Nevertheless, the July PAW was more efficient in terms of yield per unit of PAW. Thus, 1 mm of PAW within 0–150 cm in March, June and July 1st increases the MY by 16, 21 and 30 kg/ha of grain, respectively. The MY was more related to March and especially to June 1st PAW (0–150 cm) than to June‐July precipitation.

The PAW from deeper soil layers was in almost all cases better correlated with MY and more efficient. Thus, for the PAW within 0–70 cm on March, June and July 1st the simple correlation coefficients with yields were 0.69, 0.87** and 0.76* respectively while for the PAW within 0–150 cm the correlation coefficients were 0.87**, 0.96** and 0.91** respectively. Also, 1 mm of PAW within 0–100 cm on March, June and July 1st increases the yields by 23, 34 and 39 kg/ha while the PAW within 100–150 cm increases the yields by 40, 56 and 78 kg/ha respectively.

The results suggest that in this dry area the amount of yield is highly related to PAW at the beginning as well as during the growing season and that soil water may be a good index for forecasting yields as early as three month prior to harvest, except for years with weather accidents in late summer. They also show that PAW from deeper soil layers has a paramount effect on maximum corn yield.  相似文献   

3.
作物品种和化学固定剂对玉米谷物中镉和锌积累的影响   总被引:5,自引:0,他引:5  
A field experiment was conducted to investigate the effects of soil amendments(lime,nano-Si foliar solution and used diatomite) on the growth and metal uptake of three maize(Zea mays L.) cultivars grown in a Cd and Zn-contaminated acidic soil.The addition of lime significantly increased the maize grain yields and decreased the concentrations of Zn and Cd in the grains and shoots of maize when compared with the control.Among the three maize cultivars,Yunshi-5 accumulated the lowest amounts of Cd and Zn in the grain.The concentrations of Zn and Cd in the grain of Yunshi-5 conformed to the Chinese feed standards.These data revealed that a combination of low metal-accumulating maize and chemical fixation could effectively provide a barrier to prevent metals from entering the human food chain.  相似文献   

4.
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.  相似文献   

5.
Evaluation of nitrogen (N) dynamic in soil using regression equations is important for proper determination of N fertilization. A 3-year field experiment was conducted to (1) develop the best-fitted regression model relating corn grain and stover yield to soil residual ammonium (NH4)-N and nitrate (NO3)-N for corn yield prediction and (2) evaluate how such a model can be beneficial to the health of ecosystem by predicting the appropriate rates of N fertilization for corn production. Soil NH4-N and NO3-N were determined at corn harvest at the depths of 0–30 and 30–60 cm. Nitrogen fertilizer rates and soil mineral N accounted for a maximum of 93% variation in corn grain yield. Soil mineral N enhanced corn yield more than N fertilizer. Totals of 63.1 and 14.1 kg/ha of soil residual NO3-N and NH4-N were found in the 0- to 60-cm depth, indicating the importance of performing soil N tests.  相似文献   

6.
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.  相似文献   

7.
Zinc (Zn) deficiency in annual crops is very common in Brazilian Oxisols. Data are limited on Zn uptake and use efficiency during crop growth cycles. A field experiment was conducted during two consecutive years with the objective to determine shoot dry weight and Zn uptake and use efficiency in upland rice, dry bean, corn, and soybean during growth cycles. Shoot dry weight of four crops was significantly increased in an exponential quadratic fashion with increasing plant age. Rice and corn had higher shoot dry weights and grain yields than dry bean and soybean. Zinc concentration in rice and corn decreased in a quadratic fashion with increasing plant age. However, in dry bean and soybean, Zn concentration had a quadratic increase. Zinc uptake followed an exponential quadratic response in four crops, and it was higher in corn and upland rice than in dry bean and soybean. Zinc use efficiency in shoot dry‐weight production had significant quadratic responses in upland rice and soybean with increasing plant age. In corn, Zn use efficiency for shoot dry‐weight production was linear as a function of plant age. Zinc use efficiency for grain production was maximum for corn and minimum for soybean. Hence, cereals had higher Zn use efficiency than legumes.

Zinc concentration in grain of dry bean and soybean was higher than in upland rice and corn, which is a desirable quality factor for human consumption so as to avoid Zn deficiency.  相似文献   

8.
The zinc (Zn) requirements of subterranean clover (Trifolium subteraneaum L.) are well known for the predominantly marginally acidic to neutral sandy soils of southwestern Australia, but the Zn requirements of French serradella (Ornithopus sativus Brot.) and biserrula (Biserrula pelecinus L.), now also grown on these soils, is not known and were investigated in a glasshouse pot experiment. Soil was collected from field plots never treated with Zn or treated once only with 0.5 and 1.0 kg Zn/ha as Zn oxide either in 1983, 1984, 1986, 1990, 1992, 1996, 1997, or 2000. In the pot experiment, six levels of Zn were freshly-applied to samples of soil collected from each Zn treatment of the field experiment, and pots were sown either with subterranean clover cv. ‘Dalkeith’, French serradella cv. ‘Margurita’, or biserrula cv. ‘Casbah’. The pasture species were defoliated by cutting pasture herbage 3 cm above the soil surface for up to 4 consecutive defoliations. The approximate linear relationship between the level of freshly-applied Zn in the pot experiment required to produce 90% of the maximum yield of dried defoliated herbage (y-axis) and the number of years since Zn was applied in the field (x-axis) was used to project the number of years it took for the 0.5 or 1.0 kg Zn/ha treatments applied in the field to require the same level of freshly-applied Zn to produce 90% of the maximum yield of the nil-Zn treatment in the field. This was 18–19 years for the 0.5 kg Zn/ha treatment and 32–35 years for the 1.0 kg Zn/ha treatment. The range in values was due to differences between legume species and the defoliation treatments, which were not significant. When yields were measured, samples of young growth (YG) were separated from the rest of the defoliated herbage (ROH) and the concentration of Zn in YG and ROH was measured. The concentration of Zn in YG that was related to 90% of the maximum yield of defoliated dried herbage (critical tissue test value) was (mg/kg) 13 for subterranean clover, 17 for French serradella, and 19 for biserrula; respective critical tissue test values for ROH were 19, 24, and 21 mg/kg. The approximate linear relationship between critical Zn concentration in YG (y-axis) and the number of years since Zn was applied in the field (x-axis) was used to project the number of years it took for the 0.5 and 1.0 kg Zn/ha levels applied in the field to reach the same critical tissue test value as the nil-Zn treatment of the field experiment. This was 17–20 years for the 0.5 kg Zn/ha treatment and 31–37 years for the 1.0 kg/ha treatment, which was similar to the 18–19 and 32–35 years projected using yield data. Before sowing the legumes in the pot study soil samples were collected to measure soil test Zn using the DTPA procedure. The critical DTPA soil test Zn, the soil test value that was related to 90% of the maximum yield of defoliated dried herbage, was about 0.20 mg Zn/kg for the 3 pasture legume species and all Zn treatments in the field and pot studies.  相似文献   

9.
The degree of nitrogen (N) supply in maize under nonirrigated and irrigated conditions was measured using a Soil Plant Analysis Development (SPAD) 502 portable chlorophyll meter for 4 years. The lowest readings were obtained from a plot that has not been fertilized for 23 years. The highest SPAD value in the nonirrigated treatments was obtained in 2004, whereas the lowest was measured in the drought year of 2007. In the irrigated treatments, there was a closer correlation between fertilization and SPAD values during the examined 4 years. As the result of fertilization, the average increase of SPAD values in the irrigated plots was greater than in the nonirrigated plots. The result of irrigation on SPAD values was significant every year (P < 0.001), with the largest increase in the drought year of 2003. In the nonirrigated treatments, fertilization and grain yield had a weak correlation, whereas in the irrigated treatments the correlation between the two variables was strong.  相似文献   

10.
Deficiency of micronutrients is increasing in crop plants in recent years in Oxisols and Ultisols in the tropics. The predominant soils in the coastal tablelands of Brazil are Ultisols and Oxisols, with low cation exchange capacity and kaolinitic clay mineralogy. Soil copper (Cu), manganese (Mn), and zinc (Zn) extracted by the Mehlich 1 solution, currently used in the regional soil-testing laboratories, were compared with those extracted by the Mehlich 3 and diethylenetriaminepentaacetic acid (DTPA) solutions in a greenhouse experiment with 10 soil samples (0–20 cm deep) collected from representative Ultisols and Oxisols from various locations in the region. Corn was grown as a test crop, and its dry matter and micronutrient uptake was measured at 30 days of growth. Soil Cu, Mn, and Zn extracted with the three solutions were significantly correlated (0.65–0.95 range for r values), with the Mehlich 3 solution extracting greater quantities than the Mehlich 1 and DTPA solutions. Zinc and Cu taken up by corn plants were significantly related to their soil-extractable levels measured at harvest with all three of the solutions, except for Zn DTPA. However, similar relations between plant uptake and soil extractable Mn were poor, except for DTPA extracting solution.  相似文献   

11.
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.  相似文献   

12.
ABSTRACT

Blends of controlled-release urea (CRU) and conventional urea can be an alternative to conventional fertilization to improve nitrogen use efficiency (NUE) and reduce costs when applied as a single application to agricultural crops. Different indexes of NUE, grain yield, nutrient uptake and partitioning in maize (Zea mays L.) were investigated in field experiments. The treatments consisted of a single rate of 180 kg N ha?1 with different proportions of polymer-sulfur coated urea (PSCU) and conventional urea (U) applied incorporated at sowing (0.05 m below and 0.1 m to the side of the seed row) at two tropical sites (Site 1, Typic Haplustox; Site 2, Rhodic Haplustox) in Brazil. A control treatment (without urea-N) and a treatment with conventional urea management (UCM: 20% of urea-N applied as basal fertilizer and 80% of N applied as top dressing) were also included. This study demonstrates that blends of PSCU and U are efficient in supplying N throughout the maize cycle at a Typic Haplustox site when applied in a single application incorporated at sowing, resulting in high yields and adequate macronutrient uptake. PSCU improved NUE index compared to U and UCM. There was not response for N fertilization in the Rhodic Haplustox site.  相似文献   

13.
Abstract: The objective of this study was to determine how the extractant Mehlich 3 (M3) compared with other methods currently used in Ireland for determination of copper (Cu) and zinc (Zn) in soils. Samples from eight different mineral soil types, four of sandstone/shale and four of limestone origin, were analyzed for copper and zinc using M3 and conventional extractants. Herbage samples were taken from the soils and analyzed for Cu and Zn. Mehlich 3 results showed good correlation with ethylenediamine‐tetraacetic acid (EDTA)– and diethylenetriamine‐pentaacetic acid (DTPA)–extractable Cu and Zn. Inclusion of soil properties in multiple regression models improved the coefficients of determination. All extractants were equal in their ability to predict Cu and Zn herbage content. Differences between sandstone/shale and limestone soils in relation to herbage content were also found, with the better relationship found in sandstone/shale soils.  相似文献   

14.
Interaction between mycorrhizal fungi and herbicide application and their effects on plant growth are issues around which there is little information. Therefore, to determine the effect of arbuscular mycorrhizal (AM) fungus in alleviating the effects of herbicide stress on growth of maize and barley, two pot experiments were conducted in Shahrood University of Technology in 2009 and 2010. Factorial experiments were arranged in completely randomized design with three replications. Experimental factors were a combination of two factors: (1) non-mycorrhiza (control) and Glommusmosseae, Glommusintraradices and Glommusfasciculatum as mycorrhizal inoculums; (2) herbicide treatments, which included three levels of metribuzin (0, 175 and 350 g a.i. ha?1). In the second experiment, factors examined were inoculated soil with mycorrhiza fungi at two levels (with and without Glommusintraradices) and four rates of metribuzin (0, 175, 350 and 525 g a.i. ha?1) and two levels of iron (0 (control) and 20 mg pot?1). The results showed that soil inoculated with mycorrhiza had significantly increased dry weight, height and chlorophyll content of maize and barley in the low herbicide concentrations (175 g a.i. ha?1) compared to non-inoculated treatments. Based on our results, mycorrhiza fungi can alleviate crop stress due to low doses of metribuzin injury through increase in plant growth.  相似文献   

15.
Urea treated with urease inhibitors (UI) in association with humic substances (HS) is expected to improve urea efficiency by reducing ammonia losses and also provide the benefits of HS such as improve nitrogen (N) recovery by plants. Ammonia volatilization (AV), 15N recovery efficiency in the soil (NRE) and 15N use efficiency (NUE) were evaluated in maize (Zea mays L.) in a greenhouse pot trial. Treatments consisted of 15N-urea treated with UI (0, 0.4% boron (B) +0.15% copper (Cu), 0.64% B, and NBPT (N-(n-butyl) thiophosphoric triamide)) and three levels of HS (0%, 0.6%, and 1.2%). A control treatment (without N) was also included. N treatments were applied at V4 (vegetative leaf stage 4) on soil surface. HS was not efficient on AV reduction, NBPT had the greatest reduction in AV, and B had higher efficiency on AV reduction than Cu. At V8 (vegetative leaf stage 8), NBPT had the greatest NUE followed by B. At VT (tassel fully emerged), NUE from urea treated with NBPT reduced when increased levels of HS, and NBPT had the greatest NRE. UI in association with HS treated-urea does not reduce AV and it does not improve NUE by maize in vegetative stages.  相似文献   

16.
The Fe and Zn deficiency tolerances for two high yielding maize (Zea mays L.) hybrids (G‐2 and G‐5) and their parent cultivars were examined by growing them in nutrient solutions. The results indicated the occurrence of heterosis for Zn deficiency tolerance in G‐5, and to a lesser extent in G‐2. Each cultivar was susceptible to Fe deficiency and did not show signs of recovery from chlorosis. The symptoms of Fe deficiency were distinct from those for Zn deficiency. Plant growth was affected more by Fe deficiency than by Zn deficiency. The roots of cultivars were reduced in growth under Fe deficiency conditions.  相似文献   

17.
The aim of this study was to test the ability of several strains of fungi, which were isolated from the Brazilian Amazon, to solubilize calcium phosphate in vitro and to promote corn and cowpea growth under axenic conditions. Each plant species received six treatments: inoculation with strains with high solubilization index (SI) (Haematonectria ipomoeae CML 3249 and Pochonia chlamydosporia var. catenulate CML 3250) and control treatments: inoculation with strain that does not solubilize phosphate on Pikovskaya agar (PVK) (Acremonium polychromum FSA115), and non-inoculated treatments with high concentration of insoluble phosphate (HPins), high concentration of soluble phosphate (HPs) or low concentration of soluble phosphate (LPs). The fungi strains had SI between 1.07 cm and 2.03 cm including species without previous report in the literature of their capacity to solubilize calcium phosphate. The two phosphate-solubilizing strains promoted greater corn and cowpea root growth than the controls FSA115, HPins and LPs, to a level similar to the HPs control.  相似文献   

18.
Corn requires high nitrogen (N) fertilizer use, but no soil N test for fertilizer N requirement is yet available in Quebec. Objectives of this research were (1) to determine the effects of soil nitrate (NO3 ?)-N, soil ammonium (NH4 +)-N, and N fertilizer rates on corn yields and (2) to determine soil sampling times and depths most highly correlated with yields and fertilizer N response under Quebec conditions. Soil samples were taken from 0- to 30-cm and 30- to 60-cm depths at seeding and postseeding (when corn height reached 20 cm) to determine soil NH4 + and NO3 ? in 44 continuous corn sites fertilized with four rates of N in two replications using a quick test (N-Trak) and a laboratory method. The N-Trak method overestimated soil NO3 ?-N in comparison with the laboratory method. Greater coefficients of determination were observed for soil NO3 ?-N analyses at postseeding compared with seeding.  相似文献   

19.
ABSTRACT

To establish a critical limit in soils and plant, an experiment was conducted in red and lateritic soil (Alfisols) of farmer’s field in tribal-dominated Panchayat Kurum, Palkot block, Gumla district, Jharkhand, India. Based on the results of the field experiment, the critical limits were determined as 0.48, 0.50, 0.47, and 0.42 mg kg?1 in the soil, respectively, for hot water, hot calcium chloride, salicylic acid, and ammonium acetate-extractable B, while a critical limit of 12.00 mg kg?1 was observed in maize tissue using the graphical method. In an analysis of variance method, the critical limits of B in soils were found as 0.45, 0.54, 0.49, and 0.43 mg kg?1 using hot water, hot calcium chloride, salicylic acid, and ammonium acetate extractants, respectively. Maize plants were highly responsive to B application where soil B level was below the critical limit (0.50 mg kg?1). In a field experiment, grain yield of maize increased with increasing levels of B application, while soil application at 1.0 kg ha?1 + two foliar application (at the knee and pre-flowering stages) of borax at 0.2% were showed significantly higher grain yield of the maize crop. The hot water, hot calcium chloride, salicylic acid, and ammonium acetate-extractable B were significantly and positively correlated with organic carbon and negatively correlated with the electrical conductivity of soils.  相似文献   

20.
To estimate the effect of elevated [CO2] on nitrogen (N) and phosphorus (P) dynamics and productivity in summer maize, a field experiment was conducted in open-top chambers (OTCs) at different [CO2] (550 μmol/mol, T1; 750 μmol/mol, T2 and a control, CK) in Nanjing in Jiangsu Province, China. The results showed that maize total N and P accumulation were 13.23–66.56% higher in the elevated [CO2] treatments than in the CK plots during the jointing, anthesis and maturity stages. There was only a significant difference in total N accumulation between the T2 treatment and CK at maturity (P < 0.05). However, rising [CO2] decreased the N and P concentrations in each biomass fraction. Elevated [CO2] increased the amounts of N and P translocation, resulting in the contribution of translocated N to grain N. Similarly, rising [CO2] increased N and P translocation efficiencies, N or P harvest index, and N or P utilization efficiency based on grain yield and N or P utilization efficiencies based on biomass in both growing seasons. In addition, elevated [CO2] significantly increased aboveground biomass at three stages, including 4.73–12.34% at maturity. The grain yields of summer maize increased by 21.28% and 29.07% in the two elevated [CO2] plots. Furthermore, spike numbers, kernels per spike and 100-grain weight were increased by elevated [CO2] treatments. Kernels per spike and grain yield showed obvious differences between elevated [CO2] treatments and CK (p < 0.05).  相似文献   

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