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.     

Winter Wheat Yield,Quality, and Nitrogen Removal Following Compost- or Manure-Fertilized Sugarbeet

To efficiently use nitrogen (N) while protecting water quality, one must know how a second-year crop, without further N fertilization, responds in years following a manure application. In an Idaho field study of winter wheat (Triticum aestivum L.) following organically fertilized sugarbeet (Beta vulgaris L.), we determined the residual (second-year) effects of fall-applied solid dairy manure, either stockpiled or composted, on wheat yield, biomass N, protein, and grain N removal. Along with a no-N control and urea (202 kg N ha^?1), first-year treatments included compost (218 and 435 kg estimated available N ha^?1) and manure (140 and 280 kg available N ha^?1). All materials were incorporated into a Greenleaf silt loam (Xeric Calciargid) at Parma in fall 2002 and 2003 prior to planting first-year sugarbeet. Second-year wheat grain yield was similar among urea and organic N sources that applied optimal amounts of plant-available N to the preceding year’s sugarbeet, thus revealing no measurable second-year advantage for organic over conventional N sources. Both organic amendments applied at high rates to the preceding year’s sugarbeet produced greater wheat yields (compost in 2004 and manure in 2005) than urea applied at optimal N rates. On average, second-year wheat biomass took up 49% of the inorganic N remaining in organically fertilized soil after sugarbeet harvest. Applying compost or manure at greater than optimum rates for sugarbeet may increase second-year wheat yield but increase N losses as well.

Abbreviations CNS, carbon–nitrogen–sulfur     

EFFECTS OF DIFFERENT NITROGEN,PHOSPHORUS, POTASSIUM RATES ON THE QUALITY AND QUANTITY OF CITRUS PLANTS,VARIETY THOMSON NOVEL UNDER RAINFED AND IRRIGATED CONDITIONS

Plants require nutrients including nitrogen (N), phosphorus (P), and potassium (K) for their growth and production. Although there have been previously extensive research work regarding the effects of NPK on plant growth, data related to the effects of long term application of NPK on the quality and quantity of citrus under rainfed and irrigated conditions are little. Accordingly, such effects were evaluated in this research work using different chemical fertilization factorially combined and on the basis of a completely randomized block design. Using ammonium sulfate (100, 150 and 200 g tree ^{? 1}), triple super phosphate (0, 25, 50, and 75 g tree^?1) and potassium sulfate (0, 50, 100, 150 g tree ^{? 1}) the quantity and quality of citrus fruit, variety Thomson were determined in a 10-year experiment in two different research stations in Ramsar, Iran. NPK fertilization significantly affected the quality and quantity of citrus fruits, indicating the significance of NPK fertilization for citrus production.     

INFLUENCE OF HIGH TEMPERATURE AND UREA FERTILIZATION WITH N-(N-BUTYL) THIOPHOSPHORIC TRIAMIDE AND DICYANDIAMINDE ON COTTON GROWTH AND PHYSIOLOGY

The objective of this growth chamber study was to evaluate the effect of adding N-(n-butyl) thiophosphoric triamide (NBPT) and dicyandiaminde (DCD) to urea fertilizer, on the physiology and growth of cotton (Gossypiumhirsutum L.) under normal and high temperatures. Treatments consisted of two day temperature regimes, 30°C and 38°C, and five nitrogen fertilization applications: unfertilized control, 125 kg ha^?1 of urea, 93 kg ha^?1 of urea, 93 kg ha^?1 urea + NBPT, and 93 kg ha^?1 urea + NBPT + DCD. The addition of NBPT to urea fertilizer had positive effects on leaf chlorophyll, leaf area, dry matter, nitrogen (N) uptake, and N use efficiency. The absence of a significant interaction effect indicated that N fertilization was not influenced by temperature. Deficiency of N significantly decreased leaf chlorophyll, increased glutathione reductase, decreased protein and increased leaf nitrate reductase. Physiological changes under high temperature included increased plant N uptake, glutamine synthetase, leaf chlorophyll, protein content, plant height and leaf area were due to high N uptake and utilization.     

EFFICACY OF GYPSUM AND MAGNESIUM SULFATE AS SOURCES OF SULFUR TO RAPESEED IN LATERITIC SOILS

A field experiment conducted on rapeseed (Brassica juncea L.) during 2005–2006 in a typical lateritic soil (Alfisol) of West Bengal, India revealed that sources of sulfur viz. gypsum and magnesium sulfate and levels of sulfur (0, 20, 40, 60 kg S ha^?1) have significant influence on grain yield, total biological yield, sulfur concentration in grain and stover, total sulfur uptake, oil content and oil yield and chlorophyll content. The maximum grain yield (18.28 q ha^?1) and oil yield (8.59 q ha^?1) was obtained with magnesium sulfate followed by gypsum yielded the grain yield of 17.99 q ha^?1 and oil yield of 8.22 q ha^?1 at 40 kg S ha^?1. Overall, the best performance was recorded when sulfur was applied at 40 kg S ha^?1 either as magnesium sulfate or gypsum. Results revealed that magnesium sulfate may be considered as the better source of sulfur than gypsum to raise the mustard crop in sulfur deficient acidic red and lateritic soils of West Bengal and if farmers apply either magnesium sulfate or gypsum to soils, the possible deficiency of sulfur and magnesium/calcium in soils and plants can be avoided.     

YIELD AND YIELD COMPONENTS OF UPLAND RICE AS INFLUENCED BY NITROGEN SOURCES

Ammonium sulfate and urea are main sources of nitrogen (N) for annual crop production in developing countries. Two greenhouse experiments were conducted using ammonium sulfate and urea as N sources for upland rice grown on a Brazilian Oxisol. The N rates used were 0, 50, 100, 150, 3000, and 400 kg N kg^?1 of soil. Yield and yield components were significantly increased in a quadratic fashion with increasing N rate. Ammonium sulfate X urea interaction was significant for grain yield, shoot dry matter yield, panicle number, plant height and root dry weight, indicating a different response magnitude of these plant parameters to two sources of N. Based on regression equation, maximum grain yield was achieved with the application of 380 mg N kg^?1 by ammonium sulfate and 271 mg N kg^?1 by urea. Grain yield and yield components were reduced at higher rates of urea (>300 mg kg N) but these plant parameters’ responses to ammonium sulfate at higher rates was constant. In the intermediate N rate range (125 to 275 mg kg^?1), urea was slightly better compared to ammonium sulfate for grain yield. Grain yield was significantly related with plant height, shoot dry weight, panicle number, grain harvest index and root dry weight. Hence, improving these plant characteristics by using appropriate soil and plant management practices can improve upland rice yield.     

Effect of Cattle Manure and Sulfur on Yield and Oil Composition of Pumpkin (Cucurbita pepo var. Styriaca) Inoculated with Thiobacillus thiooxidans in Calcareous Soil

The effect of cattle manure and sulfur fertilizer on seed yield and oil composition of pumpkin (Cucurbita pepo var. Styriaca) under inoculated with Thiobacillus thiooxidans was investigated in a factorial study based on a randomized complete block design. Experimental factors consisted of cattle manure (M) (M₀: 0, M₁: 10; and M₂: 20 t ha^?1), sulfur (S) (S₀: 0, S₁: 250; and S₂: 500 kg ha^?1) and T. thiooxidans (B): inoculated (B₁) and non-inoculated (B₀). Results demonstrated that the application of T. thiooxidans, cattle manure, and S fertilizer decreased the soil pH. The largest number of seed per fruit (367), highest fruit yield (70.57 t ha^?1), seed iron (Fe) content (16.26 mg 100 g^?1), and seed yield (111 kg ha^?1) was obtained when 20 t ha^?1 manure was applied in combination with 500 kg ha^?1 S inoculated with T. thiooxidans. In this condition, the content of S, Fe, phosphorus (P), and nitrogen (N) in plant shoots was increased by 44.8%, 22.58%, 33.89%, and 10.38%, respectively, compared to the control. Moreover, the highest content of seed protein was observed in 10 t ha^?1 manure and 500 kg ha^?1 S fertilizer inoculated with T. thiooxidans. When 250 kg ha^?1 S fertilizer was applied, 20 t ha^?1 manure decreased seed P content sharply. At the rate of 500 kg ha^?1 S fertilizer, the highest content of seed P was obtained from 20 t ha^?1 manure. Totally, 20 t ha^?1 cattle manure, along with 500 kg ha^?1 S fertilizer as well as T. thiooxidans inoculation, improved oil and seed yield of medicinal pumpkin.     

Yellow melon yield in response to mineral or organic fertilization

Although current recommendations in Brazil suggest the application of mineral and organic fertilizers, there is little information regarding the interaction between them in melon plants. This study aimed to evaluate the effects of mineral and organic fertilization in the plant development, nutritional status, and fruit yield of yellow melon. The following fertilizations were evaluated: mineral fertilization; bovine manure; bovine manure associated with mineral fertilization; poultry litter; and poultry litter associated with mineral fertilization. Bovine manure and poultry litter were applied at rates equivalent to 15 m³ ha^?1 and 5 m³ ha^?1, respectively. Phosphorus and potassium were applied based on the results of the soil analysis and nitrogen based on the expected yield of 20 to 30 t ha^?1 of fruits. Phosphate and organic fertilizers were applied at the time of preparation of the beds, while nitrogen and potassium were supplied daily through irrigation water. Goldex F1 melon hybrid seedlings were used in the experiment. Plants were collected to evaluate the dry matter production at beginning of flowering, beginning of fruiting, fruit growth, and fruit harvest. Leaves were collected at flowering stage to evaluate the nutritional status of plants. Harvest was made when the fruits reached the intense yellow coloration. Organic fertilizers alone and combined to mineral fertilizer did not affect the dry matter yield of leaves, stems, fruits and shoot, the concentrations of macro and micronutrients in melon leaves, the nitrogen accumulation in the plant, and the yield of the yellow melon. The application of bovine manure associated to mineral fertilization showed the lowest values of nitrogen recovery applied. Bovine manure application resulted in increase of nitrogen organic forms in soil.     

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha^?1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha^?1enabled greater production of sugarcane stalks (140 t ha^?1).     

Wheat Nitrogen Fertilization Under no Till on the Low Altitude Brazilian Cerrado

This study evaluates the effects of different nitrogen (N) rates (0, 50, 100, 150, and 200 kg ha^?1) and sources (ammonium sulfate, urea, and ammonium sulfonitrate with a nitrification inhibitor, Entec®) applied either as a single application during sowing (next to the planting rows) or as side dressing (stage 3.2 on Zadok scale), on production components and grain yield of irrigated wheat grown under no-till in a low-elevation Brazilian cerrado and Dark Red Dystrophic Latosol with clayey-texture. It was adopted a randomized block design (5 × 3 × 2) in factorial scheme with four replications. The N sources provided similar grain yields and chlorophyll contents. Increased nitrogen rates increased grain yield up to the 120 kg N ha^?1, regardless of application time and N source. Nitrogen fertilization as side dressing can be recommended based on leaf chlorophyll readings. Early application of all nitrogen fertilizers at sowing time was viable.     

Yield Response of Corn to Single and Combined Application of Cattle Manure and Urea

A 2-year field experiment was conducted to evaluate the single- and combined-application effects of cattle manure and urea on corn (Zea mays L.) production. A randomized complete block design was conducted with five nitrogen (N) rates (36, 72, 108, 144, and 180 kg N ha^?1) as urea, cattle manure, or both. The stover yield and aboveground biomass increased with urea application up to 144 kg N ha^?1 but remained unchanged at greater N rates. At all N rates, combined application of manure and urea resulted in greater grain yields than single applications. Crop response to applied N was greater in the combined N application system than in the single-application treatments. The greatest grain yield was found in plots that had received a combination of 18 ton manure ha^?1 plus 160 kg urea ha^?1. Manure application along with urea enhanced crop yield response to urea and reduced its application rate.     

Effects of controlled-release urea combined with conventional urea on nitrogen uptake,root yield,and quality of Platycodon grandiflorum

Field experiments were conducted with four nitrogen fertilizer treatments to study the effects of controlled-release urea combined with conventional urea on the nitrogen uptake, root yield, and contents of protein, soluble sugar, saponin, zinc (Zn), iron (Fe), magnesium (Mg), and copper (Cu) in Platycodon grandiflorum. Field experiments were conducted with four nitrogen (N) fertilizer treatments: no N fertilization; conventional urea with N rate of 175 kg N ha^?1; conventional urea with N rate of 160 kg N ha^?1; controlled-release urea combined with conventional urea with N rate of 160 kg N ha^?1; controlled-release urea combined with conventional urea with N rate of 135 kg N ha^?1. The results showed that nitrogen application significantly increased the yield of P. grandiflorum compared with the control. Treatment with controlled-release urea combined with conventional urea at 160 kg N ha^?1 provided the highest yield of 7329.58 kg ha^?1. Nitrogen application also increased the contents of soluble sugar, total saponin, protein, Zn, Fe, and Mg but decreased Cu content. Protein, saponin, and Zn contents were significantly higher, but Cu content was lower in P. grandiflorum fertilized with controlled-release urea combined with conventional urea than those fertilized with conventional urea alone. The combination of controlled-release urea with conventional urea at 160 kg N ha^?1 was the optimal treatment under the experimental condition investigated in this study.     

Influence of Organic Residue Recycling on Crop Yield,Nutrient Uptake,and Microbial and Nutrient Status of rabi Sorghum (Sorghum bicolor L.) under Dryland Condition

The field experiment was conducted on black soil (Vertic Ustropept) at Zonal Agricultural Research Station farm, Solapur, for successive 30 years from 1987–1988 to 2016–2017 under dryland condition in a randomized block design with 10 treatments and 3 replications. The pooled results of seven years (2010–2011 to 2016–2017) revealed that the application of 25 kg N ha^?1 through crop residue (CR, byre waste) along with 25 kg N ha^-1 through Leucaena lopping (Leucaena leucocephala) to rabi sorghum gave significantly higher grain and stover yield and Sustainable Yield Index (14.61 and 36.11 q ha^?1 and 0.47, respectively) which was on par with T₇, where 25 kg N ha^?1 through farmyard manure (FYM) + 25 kg N ha^?1 through urea was applied for grain and stover yield (13.95 and 34.46 q ha^?1 and 0.44, respectively). The gross and net monetary returns and benefit–cost ratio were also influenced significantly due to integrated nitrogen management (Rs. 59,796, Rs. 47,353 ha^?1, and 3.13, respectively). This was also reflected in residual soil fertility status of soil after harvest of rabi sorghum. The organic carbon content and available nitrogen content of soil, as well as nitrogen uptake and moisture use efficiency for grain, were also increased. The total microbial count of bacteria, fungi, and actinomycetes was more where FYM or CR addition was done. The count of N fixers and P solubilizers was more under Leucaena application either alone or with CR or urea. Application of CR at 4.8 t ha^?1 (25 kg N ha^?1) along with Leucaena lopping at 3.5 t ha^?1 (25 kg N ha^?1) as green leaf manure is the best alternative organic source for fertilizer urea (50 kg N ha^?1) to increase the production of dryland rabi sorghum.     

CONTROLLED-RELEASE UREA FOR RICE PRODUCTION AND ITS ENVIRONMENTAL IMPLICATIONS

Controlled-release urea (CRU) and its placement method in rice production were investigated during 2007 and 2008 seasons. Controlled-release urea was applied at 62.5, 125, and 187.5 kg nitrogen (N) ha^?1, and the urea was 187.5 kg N ha^?1. All the CRU treatments were applied to the nursery beds once, and they were brought into the paddy field during transplanting, while the urea treatment was split into three applications from the plowing to the harvest. The results showed that rice seedlings with CRUs germinated and grow well and there was no salt damage at the nursery stage. The CRU treatment with 125 kg N ha^?1 had 33% less N than urea treatment (187.50 kg N ha^?1), but it produced significantly higher grain and straw yields, higher total N uptake and total apparent N uptake efficiency. In addition, all the CRU treatments effectively decreased floodwater ammonium (NH₄ ⁺)-N and nitrate (NO₃ ^?)-N concentrations, pH, and N runoff.     

MODULATION IN YIELD AND JUICE QUALITY CHARACTERISTICS OF CITRUS FRUIT FROM TREES SUPPLIED WITH ZINC AND POTASSIUM FOLIARLY

Citrus, especially K innow (Citrus deliciosa × Citrus nobilis), fruit yield and quality in Pakistan is not competitive with that of other countries which could be mainly attributed to the lack of good nutrient management for citrus orchards. The yield losses in this fruit crop occur mainly due to heavy fruit dropping. Experiments to overcome these problems were conducted at four different sites one each in Faisalabad, Toba Tek Singh, Jhang and Sargodha districts of Punjab, Pakistan. The soil and leaf chemical analysis showed severe deficiency of Zn and our pervious results have shown that soil amendment with potassium (K) at 75 K₂O kg ha^?1 improved the citrus fruit yield and quality at all selected sites. In the present experiments, effect of foliar application of Zn and K alone or in combination was studied on nutrient uptake, fruit yield, fruit dropping and juice quality. The fruit trees were pretreated with a selected K level of sulfate of potash (SOP) or muriate of potash (MOP), i.e., 75 kg K₂O ha^?1 along with recommended nitrogen (N) and phosphorus (P) doses. Zinc [Zn, 1% zinc sulfate (ZnSO₄) solution], K [1% potassium sulfate (K₂SO₄) solution] and Zn + K (solution containing 0.5% each of ZnSO₄ and K₂SO₄) were sprayed at the onset of spring and flush of leaves or flowers, fruit formation and at color initiation on fruit. Overall, application of Zn, K or Zn + K was effective in improving the nutrient uptake, yield and quality parameters of citrus fruit at all sites. Fruit dropping was also reduced by the foliar spray of Zn, K or Zn + K but the most promising results were recorded with foliar spray containing both Zn and K.     

Alleviation of salinity stress in red cabbage plants by urea and sulfur applications

Environmental stresses, such as salinity, are becoming critical constraints to plant production especially in arid and semi-arid regions, one of the main targets of agricultural studies is to combat the environmental stresses on plants. An open field experiment was carried out to study the influence of sulfur (S) and urea on red cabbage plants under salt stress. The experiment was arranged as a split-plot design with three replications, the main plots included sulfur levels (0, 350, and 700 kg ha^?1), while subplots included urea levels (0, 1, 2, and 4 g L^?1). Results showed that urea spraying and sulfur soil additions resulted in improvement of growth and yield, and raised the level of potassium and nitrogen while lowering sodium content in plant leaves under salt stress conditions. Generally, larger and heavier heads were found with the application of 700 kg ha^?1 sulfur and 2 g L^?1 urea.     

Integrated Fertilizer Management: Influence on Soil Nitrogen,Available Phosphorus,Potassium, Nutrient Uptake and Maize Yield

A field experiment was conducted on an Alfisol (kandic paleustalf) in Abeokuta, Southwestern Nigeria, for two seasons to assess the influence of inorganic and organic fertilizers on nitrogen (N), phosphorus (P), potassium (K), nutrient uptake and maize yield. The treatments consisted of three rates of organic fertilizer 0, 5 and 10 t ha^?1 in the form of poultry manure and NPK fertilizer (20:10:10) applied at 0 and 120 kg ha^?1. Maize (Zea mays) was used as the test crop. The results showed that the combined application of 10 t ha^?1 poultry manure and 120 kg ha^?1 NPK fertilizer enhanced the uptake of N, P and K better than other treatment combinations. Application of 10 t ha^?1 poultry manure alone gave the highest grain yield, which was 67.02% higher than the control in the first season. Complementary application of 5 t ha^?1 poultry manure with 120 kg ha^?1 NPK 20–10-10 was recommended for grain yield.     

Nitrogen source and application method impact on corn yield and nutrient uptake

Farmers are looking for better management practices to utilize animal manure as an alternative to chemical fertilizers. A 2-year field experiment was conducted to study the effects of nitrogen (N) fertilizer source and application methods to Nicholson silt loam soil in central Kentucky, USA for no-till corn (Zea mays) production. The region has a temperate climate with a mean temperature of 14.5°C and rainfall of 1300 mm year^?1. Treatments included a control, 179 kg N ha^?1 urea ammonium nitrate (UAN) applied as preplant and sidedress, and swine effluent that was applied by three methods: broadcast, injection, and Aerway. Injection method produced the greatest corn grain yield (11.88 Mg ha^?1) and biomass yield (18.9 Mg ha^?1) in 2007. Results demonstrated that the effluent application methods and the timing of UAN application may not be agronomically important for corn production in this region. Hence, more studies are needed on different soils in this region.     

Soil Inorganic Nitrogen Content and Indices of Red Raspberry Yield,Vigor, and Nitrogen Status as Affected by Rate and Source of Nitrogen Fertilizer

Abstract

The single‐year response of soil inorganic nitrogen (N) content and indices of red raspberry (Rubus ideaus L.) yield, vigor, and N status to rate and source of fertilizer N were determined. Twenty‐nine trials were conducted in commercial plantings from 1994 to 1996. Treatments were 0, 55, or 110 kg N ha^?1 as ammonium nitrate or 55 kg N ha^?1 as a slow‐release fertilizer product containing 60% polycoated sulfur‐coated urea and 40% urea. Soil nitrate (NO₃) content frequently increased during the growing season, indicating that soil N supply was nonlimiting. The plant indices were generally insensitive to fertilizer‐N rate under these high‐N fertility conditions. Soil nitrate content measured after berry harvest was frequently excessive even at the recommended N rate and can be used to identify fields with excess N fertility. The slow‐release N fertilizer provided limited benefits compared with use of ammonium nitrate.     

Response surface optimization of cultivation conditions for yield of tomato (Lycopersicon esculentum Mill.) in greenhouses

There is a great potential for greenhouse tomato fruit yield improvement in China for the low yield per hectare. We evaluated the effects of multi-factors (plant density, nitrogen (N) and K₂O fertilizer) on fruit yield of tomato (Lycopersicon esculentum Mill. cv. Jinfan 4) by response surface methodology with a 5-level-3-factor central composite design. A multivariate quadratic regression model of fruit yield was established. Results showed that N fertilizer was the most significant for fruit yield, followed by K₂O fertilizer and plant density. Fruit yield showed a parabolic trend with increasing fertilizer levels or plant density. There was a significant interaction effect between plant density and fertilizer levels. Optimal conditions were obtained: 4.83 × 10⁴ plants ha^?1 for density, 262 kg ha^?1 for N and 513 kg ha^?1 for K₂O. Under these conditions, the predicted fruit yield was 119,381 kg ha^?1, while the actual fruit yield from verification test was 121,005 kg ha^?1.