Integrated Effects of Mulching Treatment and Nitrogen Fertilization on Cotton Performance under Dryland Agriculture

ABSTRACT

Crop production in arid regions is characterized with high temperature, drought and salinity which decrease water and nutrient use efficiency. This study was conducted to investigate the effect of wheat residue mulch in relation to N fertilizer application rates for cotton productivity under dryland condition of Uzbekistan. Main plots were control of no mulch addition and a 5 t ha^?1 mulch treatment. These plots were split into 5 N rate plots of 0, 70, 140, 210 or 280 kg of N ha^?1. The results showed that mulching pattern decreased soil temperature by 0.7–1.5°C as compared to conventional treatment (CT), regardless of N fertilization rates. The soil water storage increased by 41.8, 17.3, 48.0 mm in the flowering, boll formation and ripening stages of cotton, respectively under mulching treatment. Soil available N concentration and nutrients uptake by plants consistently increased with the increase of N fertilization rates with positive correlations. At flowering period, the plant height, chlorophyll content, stem diameter, and a number of fruit branches in plants were higher by 32.3%, 46.8%, 26.7% and 55.3%, respectively at 210 kg N ha^?1 under mulching treatment as compared to the non-fertilized control. The highest cotton yield was obtained at 210 kg N ha^?1 application under mulching treatment. The correlation difference between mulch and N application rates was higher (R² = 0.97) than the difference in CTs and N application rates (R² = 0.89). This study showed that mulching had a greater impact to preserve nutrients and water resources in the soil, thereby improved cotton growth and yield.     

Genotypic Differences in Dry Bean Yield and Yield Components as Influenced by Nitrogen Fertilization and Rhizobia

Dry bean (Phaseolus vulgaris L.) is an important legume worldwide and nitrogen (N) is most yield limiting nutrients. A field experiment was conducted for two consecutive years to evaluate response of 15 dry bean genotypes to nitrogen and rhizobial inoculation. The N and rhizobia treatments were (i) control (0 kg N ha^?1), (ii) seed inoculation with rhizobia strains, (iii) seed inoculation with rhizobia strains + 50 kg N ha^?1, and (iv) 120 kg N ha^?1. Straw yield, grain yield, and yield components were significantly influenced by N and rhizobial treatments. Grain yield, straw yield, number of pods m^?2, and grain harvest index were significantly influenced by year, nitrogen + rhizobium, and genotype treatments. Year × Nitrogen + rhizobium × genotype interactions were also significant for these traits. Hence, these traits varied among genotypes with the variation in year and nitrogen + rhizobium treatments. Inoculation with rhizobium alone did not produce maximum yield and fertilizer N is required in combination with inoculation. Based on grain yield efficiency index, genotypes were classified as efficient, moderately efficient, and inefficient in nitrogen use efficiency (NUE). NUE defined as grain produced per unit N applied decreased with increasing N rate. Overall, NUE was 23.17 kg grain yield kg^?1 N applied at 50 kg N ha^?1 and 13.33 kg grain per kg N applied at 120 kg N ha^?1.     

Improving dryland cropping system nitrogen balance with no‐tillage and nitrogen fertilization

Studies on N balance due to N inputs and outputs and soil N retention to measure cropping system performance and environmental sustainability are limited due to the complexity of measurements of some parameters. We measured N balance based on N inputs and outputs and soil N retention under dryland agroecosystem affected by cropping system and N fertilization from 2006 to 2011 in the northern Great Plains, USA. Cropping systems were conventional tillage barley (Hordeum vulgaris L.)–fallow (CTB‐F), no‐tillage barley–fallow (NTB‐F), no‐tillage barley–pea (Pisum sativum L.) (NTB‐P), and no‐tillage continuous barley (NTCB). In these cropping systems, N was applied to barley at four rates (0, 40, 80, and 120 kg N ha^?1), but not to pea and fallow. Total N input due to N fertilization, pea N fixation, soil N mineralization, atmospheric N deposition, nonsymbiotic N fixation, and crop seed N and total N output due to grain N removal, denitrification, volatilization, N leaching, gaseous N (NO_x) emissions, surface runoff, and plant senescence were 28–37% greater with NTB‐P and NTCB than CTB‐F and NTB‐F. Total N input and output also increased with increased N rate. Nitrogen accumulation rate at the 0–120 cm soil depth ranged from –32 kg N ha^?1 y^?1 for CTB‐F to 40 kg N ha^?1 y^?1 for NTB‐P and from –22 kg N ha^?1 y^?1 for N rates of 0 kg N ha^?1 to 45 kg N ha^?1 y^?1 for 120 kg N ha^?1. Nitrogen balance ranged from 1 kg N ha^?1 y^?1 for NTB‐P to 74 kg N ha^?1 y^?1 for CTB‐F. Because of increased grain N removal but reduced N loss to the environment and N fertilizer requirement as well as efficient N cycling, NTB‐P with 40 kg N ha^?1 may enhance agronomic performance and environmental sustainability while reducing N inputs compared to other management practices.     

Phosphorus–microbes interaction on growth,yield and phosphorus-use efficiency of irrigated cotton

The phosphorus-use efficiency of crops in high pH soil is low. A randomized complete block design in a 3 × 2 split-plot experiment was conducted on a high pH silt loam (Typic Ustochrepts) to evaluate whether P-solubilizing microbial (PSM) inocula were able to improve the P fertilization effects on irrigated cotton (Gossypium hirsutum L., cultivar CIM-482). Cotton was planted after seed treatment with PSM inoculation at 0, 22 and 44 kg P ha^?1. Results showed that soil microbial populations were significantly higher throughout the cotton-growing season in response to P fertilization and PSM inoculation. Both P fertilization and PSM inocula exerted a significant effect on cotton biomass and Puptake without an interaction. Economic analyses suggest that PSM inocula alone significantly increased P-use efficiency (8%), reduced cost and improved net income (by $36 ha^?1) of irrigated cotton production. Moreover, the relationship between relative yield and P fertilization with PSM inocula showed that 95% of the maximum yield of cotton was produced at 22 kg P ha^?1, whereas in the absence of PSM inocula, 95% relative yield was obtained at 36 kg P ha^?1, asaving of ～39% applied P with PSM inoculation.     

Uptake and nutrient balance of nitrogen,sulfur, and boron for optimal canola production in eastern Canada

Balanced plant nutrition is essential to achieve high yields of canola (Brassica napus L.) and get the best economic return from applied fertilizers. A field study was conducted at nine site‐years across eastern Canada to investigate the effects of nitrogen (N), sulfur (S) and boron (B) fertilization on canola nutrient uptake, nutrient balance, and their relationship to canola yields. The factorial experiment consisted of four N rates of 0 (N0), 50 (N50), 100 (N100), and 150 (N150) kg ha^?1, two S rates of 0 (S0) and 20 (S20) kg ha^?1, and three B treatments of 0 (B0), 2 kg ha^?1 at preplant (B2.0P), and 0.5 kg B ha^?1 foliar‐applied at early flowering stage (B0.5F). Each site‐year used the same experimental design and assigned treatments in a randomized complete block design with four replications. Fertilizer S application greatly improved seed yields at six out of nine site‐years, and the highest N use efficiency was in the N150+S20 treatment. Sulfur application generally increased seed S concentration, seed S removal, and plant total S uptake, while B fertilization mainly elevated straw B concentration and content, with minimal effect on seed yields. At the early flowering stage, plant tissue S ranged from 2.2 to 6.6 mg S g^?1, but the N : S ratio was over or close to the critical value of 12 in the N150+S0 combination at five site‐years. On average across nine site‐years, canola reached a plateau yield of 3580 kg ha^?1 when plants contained 197 kg N ha^?1, 33 kg S ha^?1 and 200 g B ha^?1, with a seed B content of 60 g B ha^?1. The critical N, S, and B values identified in this work and their potential for a posteriori nutrient diagnosis of canola should be useful to validate fertilizer requirements for canola production in eastern Canada.     

Developing nitrogen management strategies under drip fertigation for wheat and maize production in the North China Plain based on a 3‐year field experiment

The intensive winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) cropping systems in the North China Plain (NCP) rely on the heavy use of mineral nitrogen (N) fertilizers. As the fertigated area of wheat and maize in the NCP has grown rapidly during recent years, developing N management strategies is required for sustainable wheat and maize production. Field experiments were conducted in Hebei Province during three consecutive growth seasons in 2012–2015 to assess the influence of different N fertigation rates on N uptake, yield, and nitrogen use efficiency [NUE: recovery efficiency (RE_N) and agronomic efficiency (AE_N)]. Five levels of N application, 0 (FN₀), 40 (FN_40%), 70 (FN_70%), 100 (FN_100%), and 130% (FN_130%) of the farmer practice rate (FP: 250 kg N ha^?1 and 205.5 kg N ha^?1 for wheat and maize, respectively), corresponding to 0, 182.2, 318.9, 455.5, and 592.2 kg N ha^?1 y^?1, respectively, were tested. Nitrogen in the form of urea was dissolved in irrigation water and split into six and four applications for wheat and maize, respectively. In addition, the treatment “drip irrigation + 100% N conventional broadcasting” (DN_100%) was also conducted. All treatments were arranged in a randomized complete block design with three replications. The results revealed the significant influence of both N fertigation rate and N application method on grain yield and NUE. Compared to DN_100%, FN_100% significantly increased the 3‐year averaged N recovery efficiency (RE_N) by 0.09 kg kg^?1 and 0.04 kg kg^?1, and the 3‐year averaged N agronomic efficiency (AE_N) by 2.43 kg kg^?1 and 1.62 kg kg^?1 for wheat and maize, respectively. Among N fertigation rates, there was no significant increase in grain yield in response to N applied at a greater rate than 70% of FP due to excess N accumulation in vegetative tissues. Compared to FN_70%, FN_100%, and FN_130%, FN_40% increased the RE_N by 0.17–0.57 kg kg^?1 and 0.03–0.34 kg kg^?1and the AE_N by 4.60–27.56 kg kg^?1 and 2.40–10.62 kg kg^?1 for wheat and maize, respectively. Based on a linear‐response relationship between the N fertigation rate and grain yield over three rotational periods it can be concluded that recommended N rates under drip fertigation with optimum split applications can be reduced to 46% (114.6 kg N ha^?1) and 58% (116.6 kg N ha^?1) of FP for wheat and maize, respectively, without negatively affecting grain yield, thereby increasing NUE.     

Nutrient flows and balances in intensively managed vegetable production of two West African cities

This study reports and analyzes nutrient balances in experimental vegetable production systems of the two West African cities of Tamale (Ghana) and Ouagadougou (Burkina Faso) over a two‐year period comprising thirteen and eleven crops, respectively. Nutrient‐use efficiency was also calculated. In Tamale and Ouagadougou, up to 2% (8 and 80 kg N ha^?1) of annually applied fertilizer nitrogen were leached. While biochar application or wastewater irrigation on fertilized plots did not influence N leaching in both cities, P and K leaching, as determined with ion‐absorbing resin cartridges, were reduced on biochar‐amended plots in Tamale. Annual nutrient balances amounted to +362 kg N ha^?1, +217 kg P ha^?1, and –125 kg K ha^?1 in Tamale, while Ouagadougou had balances of up to +692 kg N ha^?1, +166 kg P ha^?1, and –175 kg K ha^?1 y^?1. Under farmers' practice of fertilization, agronomic nutrient‐use efficiencies were generally higher in Tamale than in Ouagadougou, but declined in both cities during the last season. This was the result of the higher nutrient inputs in Ouagadougou compared to Tamale and relatively lower outputs. The high N and P surpluses and K deficits call for adjustments in local fertilization practices to enhance nutrient‐use efficiency and prevent risks of eutrophication.     

Effect of nutrient‐management practices on growth,fruiting pattern,and yield of Asiatic cotton (Gossypium arboreum L.)

Asiatic cotton (Gossypium arboreum) is mostly grown in the rainfed regions of India. However, little is known about the effects of nutrient‐management practices on plant growth and fruiting pattern of Asiatic cotton. Therefore, plant growth and fruiting pattern under four nutrient‐management treatments, N, NPK, FYM (10 Mg ha^–1), and INM (integrated nutrient management: a combination of NPK and FYM) were quantified during 2000–01 to 2002–03 (years 16 to 18 of a long‐term field experiment). Plants of the INM and FYM treatments were taller (68.4–149.5 cm) and had more main stem nodes per plant (30.5–44.5) as compared to N and NPK treatments. In treatment N, the shortest plants (50.9–83.6 cm) and the least number of fruiting structures were produced. Plants of the INM and FYM treatments accumulated more squares and bolls. Maximum boll production was 10–19 days earlier with the manure‐amended than the N and NPK treatments. Treatment N had the lowest seed cotton yield (639–790 kg ha^–1), because of small boll size (1.48–1.73 g) and few open bolls. Seed cotton yield followed the trend: NPK (815–1278 kg ha^–1) < INM (776–1551 kg ha^–1) < FYM (902–1593 kg ha^–1). Water stress and nutrient deficiencies (P and Zn in the N and Zn in the NPK treatments) as a consequence of nutrient depletion over the years may have decreased seed cotton yields in treatments that received mineral fertilizer alone in comparison with manure‐amended treatments. On a long‐term basis, FYM application should therefore form an integral part of nutrient recommendation.     

Adjusting Midseason Nitrogen Rate Using a Sensor-Based Optimization Algorithm to Increase Use Efficiency in Corn

ABSTRACT

This study was conducted to formulate an in-season nitrogen (N) fertilization optimization algorithm (NFOA) to estimate midseason N rates that maximize corn (Zea mays L.) growth and minimize fertilizer inputs. Treatments included: a zero kg N ha^?1; three treatments of 134 kg N ha^?1 fixed rate applied in split, preplant, or sidedress; two treatments of 67 kg N ha^?1 fixed rate preplant or sidedress applied; three NFOA-based midseason N rates (RI-NFOA, RICV-NFOA, flat-RICV-NFOA) with (67 kg N ha^?1) and without preplant N; and two resolutions (0.34 and 2.32 m²) tested for RICV-NFOA only. With the 67 kg N ha^?1 preplant application, midseason RI-NFOA-based N rates resulted in an N use efficiency (NUE) of 65% while the 134 kg N ha^?1 fixed rate split applied had 56% NUE. Using the RICV-NFOA, NUE and net returns to N fertilizer were higher when spatial variability was treated at 2.32 m² resolution.     

Effects of cotton (Gossypium hirsutum L.) straw and its biochar application on NH3 volatilization and N use efficiency in a drip-irrigated cotton field

Reducing ammonia (NH₃) volatilization is a practical way to increase nitrogen (N) fertilizer use efficiency (NUE). In this field study, soil was amended once with either cotton (Gossypium hirsutum L.) straw (6 t ha^?1) or its biochar (3.7 t ha^?1) unfertilized (0 kg N ha^?1) or fertilized (450 kg N ha^?1), and then soil inorganic N concentration and distribution, NH₃ volatilization, cotton yield and NUE were measured during the next two growing seasons. In unfertilized plots, NH₃ volatilization losses in the straw-amended and biochar-amended treatments were 38–40% and 42–46%, respectively, less than that in control (i.e., unamended soil) during the two growing seasons. In the fertilized plots, NH₃ volatilization losses in the straw-amended and biochar-amended treatments were 30–39% and 43–54%, respectively, less than that in the control. Straw amendment increased inorganic N concentrations, cotton yield, cotton N uptake and NUE during the first cropping season after application, but not during the second. In contrast, biochar increased cotton N uptake and NUE during both the first and the second cropping seasons after application. Furthermore, the effects of biochar on cotton N uptake and NUE were greater in the second year than in the first year. These results indicate that cotton straw and cotton straw biochar can both reduce NH₃ volatilization and also increase cotton yield, N uptake and NUE. In addition, the positive effects of one application of cotton straw biochar were more long-lasting than those of cotton straw.     

Biomass production of Lolio‐Cynosuretum grassland is not increased by plant‐species richness

In experimental grasslands, a positive relationship between biomass production and plant diversity has often been found. Here, we compared a moderately species‐rich old sward with its grass‐dominated counterpart (12 vs. 8 species per 2.5 m², or 8.3 vs. 0.7% yield proportion of dicots at the start of the experiment) established by herbicide application. We hypothesized an increased N, P and K uptake in the diverse sward related to a higher colonization rate with arbuscular mycorrhizal fungi (AMF), the presence of legumes, and complementary nutrient use of plant species. Phosphorus or N fertilizer application (according to contributions of AMF or legumes) were expected to balance the assumed smaller biomass production of the grass compared to the diverse sward. In two experimental years, N, P and K uptake, biomass production, N₂ fixation, and intra‐ and extraradical AMF colonization were investigated in an untreated control and plots that were fertilized with P and N in a low (P1: 20 kg P ha^?1; N1: 50 kg N ha^?1) or a high dose (P2: 100 kg P ha^?1; N2: 500 kg N ha^?1) in both swards. Biomass production was larger in the grass compared to the diverse sward. The N, P and K uptake, accumulated over three harvests (or 1.5 years), was also larger in the grass sward. The biomass production ranged from 5.3 to 10.0 t ha^?1 and accumulated nutrient uptake from 82 to191 kg N ha^?1, 19 to 31 kg P ha^?1 and 112 to 221 kg K ha^?1. Small legume proportions resulted in an accumulated N₂ fixation between 0 and 3 kg ha^?1. In the second year, the root length colonized with AMF structures was larger in the diverse compared to the grass sward, and the root length colonized with arbuscules and coils was larger in the N2 treatment compared to the control in the diverse sward. There were hints to higher AMF abundance under conditions of limited P availability (low soil P content, high N:P ratio in plant biomass). We conclude that in semi‐natural grassland of moderate species richness several factors may affect the relationship between plant diversity and productivity, i.e., management, plant species identity, and the number of the plant species of the low‐diversity level.     

Effects of phosphate‐solubilizing microorganisms on strawberry yield and nutrient concentrations

Phosphorus (P)‐solubilizing bacteria and fungi can increase soil‐P availability, potentially enhancing crop yield when P is limiting. We studied the effectiveness of Bacillus FS‐3 and Aspergillus FS9 in enhancing strawberry (Fragaria × ananasa cv. Fern) yield and mineral content of leaves and fruits on a P‐deficient calcareous Aridisol in Eastern Anatolia, Turkey. The 120 d pot experiment was conducted in three replicates with three treatments (Bacillus FS‐3, Aspergillus FS9, control) and five increasing rates of P addition (0, 50, 100, 150, and 200 kg P ha^–1). Fruit yield and nutrient content of fruits and leaves and soil P pools were determined at the end of the experiment. Phosphorus‐fertilizer addition increased all soil P fractions. Strawberry yield increased with P addition (quadratic function) reaching a maximum of 94 g pot^–1 at 200 kg P ha^–1 in the absence of P‐solubilizing microorganisms. At this yield level, Bacillus FS‐3 and Aspergillus FS9 inoculation resulted in P‐fertilizer savings of 149 kg P ha^–1 and 102 kg P ha^–1, respectively. Both microorganisms increased yields beyond the maximum achievable yield with sole P‐fertilizer addition. Microorganism inoculation increased fruit and leaf nutrient concentrations (N, P, K, Ca, and Fe) with the largest increases upon addition of Bacillus FS‐3. We conclude that Bacillus FS‐3 and Aspergillus FS9 show great promise as yield‐enhancing soil amendments in P‐deficient calcareous soils of Turkey. However, moderate additions of P fertilizer (50–100 kg ha^–1) are required for highest yield.     

Effects of Nitrogen Fertilization on Upland Rice based on Pot Experiments

Abstract

Limited information is available regarding the utilization and loss of fertilizer nitrogen (N) applied to intensively managed upland rice. Effects of N fertilization on upland rice were conducted as N0 (no N applied), N225 (225 kg N · ha^?1), N300 (300 kg N · ha^?1), and N375 (375 kg N · ha^?1) in pot experiments. ¹⁵N‐labeled techniques were used in basal and topdressing N fertilizations. Results showed with the increase of N quantity applied, tiller, panicle numbers per pot, and spikelet number per panicle increased significantly (P<0.05). Chlorophyll b content of N225 and N300 were significantly higher than N0 (P<0.05), and net photosynthetic rate (Pn) of N300 increased significantly compared with N0 and N225. Under basal fertilization, N use efficiency (NUE) of root, stem, leaf, and grain in N300 was the highest. The NUE and loss rate ranged from 23.3% to 30.3% and 62.4% to 73.8%, respectively, under basal fertilization. They varied from 16.5% to 27.5% and 70.7% to 80.4%, respectively, under topdressing fertilization. The highest NUE was observed in N300 under basal fertilization. As increased quantities of N were applied, Pn and biological characteristics improved, thus crop yield of upland rice increased. Grain yield of N300 and N375 were significantly higher than that of N0 and N225 (P<0.01); however, there was no significant difference between them. Therefore, N fertilization with medium applied quantity under basal fertilization will facilitate growing, photosynthesis, and grain yield increase of upland rice.     

Wheat response to N2 fixed by faba bean (Vicia faba L.) as affected by sulfur fertilization and rhizobial inoculation in semi‐arid Northern Ethiopia

Nitrogen fixation in faba bean (Vicia faba cv. Mesay) as affected by sulfur (S) fertilization (30 kg S ha^–1) and inoculation under the semi‐arid conditions of Ethiopia was studied using the ¹⁵N‐isotope dilution method. The effect of faba bean–fixed nitrogen (N) on yield of the subsequent wheat crop (Triticum aestivum L.) was also assessed. Sulfur fertilization and inoculation significantly (p < 0.05) affected nodulation at late flowering stage for both 2004 and 2005 cropping seasons. The nodule number and nodule fresh weighs were increased by 53% and 95%, relative to the control. Similarly, both treatments (S fertilization and inoculants) significantly improved biomass and grain yield of faba bean on average by 2.2 and 1.2 Mg ha^–1. This corresponds to 37% and 50% increases, respectively, relative to the control. Total N and S uptake of grains was significantly higher by 59.6 and 3.3 kg ha^–1, which are 76% and 66% increases, respectively. Sulfur and inoculation enhanced the percentage of N derived from the atmosphere in the whole plant of faba bean from 51% to 73%. This corresponds to N₂ fixation varying from 49 to 147 kg N ha^–1. The percentage of N derived from fertilizer (%Ndff) and soil (%Ndfs) of faba bean varied from 4.3% to 2.8 %, and from 45.1% to 24.0%, corresponding to the average values of 5.1 and 47.9 kg N ha^–1. Similarly, the %Ndff and %Ndfs of the reference crop, barley, varied from 8.5 % to 10.8% and from 91.5% to 89.2%, with average N yields of 9.2 and 84.3 kg N ha^–1. Soil N balance after faba bean ranged from 13 to 52 kg N ha^–1. Beneficial effects of faba bean on yield of a wheat crop grown after faba bean were highly significant, increasing the average grain and N yields of this crop by 1.11 Mg ha^–1 and 30 kg ha^–1, relative to the yield of wheat grown after the reference crop, barley. Thus, it can be concluded that faba bean can be grown as an alternative crop to fallow, benefiting farmers economically and increasing the soil fertility.     

Sweet Sorghum [Sorghum bicolor (L.) Moench] Biomass Production for Biofuel and the Effects of Soil Types and Nitrogen Fertilization

This research aimed to determine the optimum nitrogen fertilization rate on three soils for producing biomass sweet sorghum (Sorghum bicolor cultivar M81E) and corn (Zea mays cultivar P33N58) grain yield and to compare their responses. The research was conducted in Missouri in rotations with soybean, cotton, and corn. Seven rates of nitrogen (N) were applied. Sweet sorghum dry biomass varied between 11 and 27.5 Mg ha^?1) depending on year, soil type, and N rate. Nitrogen fertilization on the silt and sandy loam soils had no effect (P > 0.05) on sweet sorghum yield grown after cotton and soybean. However, yield increased in the clay soil. Corn grain yielded from 1.3 to 12.9 Mg ha^?1, and 179 to 224 kg N ha^?1 was required for maximum yield. Increasing biomass yield required N application on clay but not on silt loam and sandy loam in rotations with soybean or cotton.     

Field-level comparison of nitrogen rates and application methods on maize yield,grain quality and nitrogen use efficiency in a humid environment

Appropriate nitrogen (N) management practices are of critical importance in improving N use efficiency (NUE), maize (Zea mays) yield and environmental quality. A six-year (2005–2010) on-farm trial was conducted in Ottawa, Canada to assess the effects of N rates and application methods on grain yield and NUE. In four out of the six-year study, grain yield increased by 60–77 kg ha^?1 by sidedress, compared to 49–66 kg ha^?1 for each kg N ha^?1 applied at preplant. Grain yield response to N between the two strategies was similar in the other growing seasons. Sidedress strategy required 15 kg N ha^?1 less of the maximum economic rate of N (MERN) than preplant application. Our results indicate that sidedress application of 90–120 kg N ha^?1 with a starter of 30 kg N ha^?1 resulted in greater yield, grain quality and NUE than preplant N application in this cool, humid and short growing-season region.     

Performance of chickpea (Cicer arietinum L.) to bio-fertilizer and nitrogen application in arid condition

Abstract

Field experiments were conducted during 2013–2014 at Tashkent, Uzbekistan to evaluate the performance of chickpea variety “Jakhongir” with the variable proportion of nitrogen (N) and bio-fertilizer inoculation in the moderate saline (5.6?±?0.6?dSm^?1) soil condition. The studied treatments were No control (non-fertilized), N1 mineral-N (50?kg?N?ha^?1), N2, mineral-N (75?kg?N?ha^?1), N3, mineral-N (100?kg?N?ha^?1) equivalent 0%, 50%, 75%, and 100% from recommended rate for chickpea, Rhizobium inoculation (Bio)?+?No control, Rhizobium inoculation (Bio)?+?N1, Rhizobium inoculation (Bio)?+?N2, and Rhizobium inoculation (Bio)?+?N3. Seed inoculation with Rhizobium was significantly superior over no inoculation treatments at all rate of N fertilization. The middle rate of N fertilization 75?kg?N?ha^?1 combined with biofertilizer inoculation had of superior effect on chickpea, producing 73.2% more yield (1.68?Mg ha^?1), oil, protein, and sugar content performed 16.4%; 15.0%, and 17.9% higher value, respectively, in comparison to control.     

Agronomic Assessment of Nitrogen Use Efficiency in Spring Wheat and Interrelations with Leaf Greenness Under Field Conditions

Four spring wheat genotypes (Triticum aestivum L.) were grown without (N0 = 0 kg N ha^?1) and under ample (N1 = 250 kg ha^?1) nitrogen (N) fertilizer in field experiments in two seasons. The aim was to assess genotypic variation in N use efficiency (NUE) components and N-related indices during grain filling thus to identify superior wheat genotypes. Leaf chlorophyll (SPAD) readings at crucial growth stages were employed to help differentiate genotypes. Interrelations between yield and N-related indices with SPAD, where also assessed to explain possible pathways of improving NUE early in the growing season. Results showed that genotypic effects on NUE were mostly evident in 2000, a year with drier preanthesis and wetter postanthesis than the normal periods. ‘Toronit’ almost always had the highest biomass yield (BY) and grain yield (GY). Except in 1999 under N0, ‘L94491? showed the highest % grain N concentration (GNC). Genotypes affected SPAD at almost all stages and N fertilization delayed leaf senescence for all genotypes and growth seasons. Correlations between SPAD at different growth stages and GY, N biomass yield at maturity (NBYM) and GNC were significant (P≤ 0.001), positive and strong/very strong (>r = 0.7). N translocation efficiency (NTE) was inversely related to PANU (~r = ? 0.77, P≤ 0.001), suggesting that N after anthesis is being preferentially transported to the ears to meet the N demand of the growing grains. It is concluded that there is still a large potential for increased NUE by improved N recirculation, use of fast and inexpensive crop N monitoring tools and high yielding, N uptake efficient genotypes.

Abbreviations: NUE, Nitrogen use efficiency; SPAD, Minolta SPAD-502 chlorophyll meter, NHI, nitrogen harvest index; HI, Harvest index; NTE, N translocation efficiency from vegetative plant parts to grain; DMTE, dry matter translocation efficiency; CPAY, contribution of pre-anthesis assimilates to yield; PANU, Post-anthesis N uptake, d.a.s., days after sowing, N0, zero (0) kg ha^?1 applied N fertilizer, N1, 250 kg ha^?1 applied N fertilizer.     

Long-Term Fertilization Effects on Rice Productivity and Nutrient Efficiency in Korean Paddy

ABSTRACT

Long-term fertilization tests evaluated rice (Oryza sativa) productivity in relation to application of nitrogen (N)-phosphorus (P)-potassium (K) (120-34.9-66.7 kg ha^{? 1}, respectively) during 1967–1972 and N-P-K (150-43.7-83.3 kg ha^{? 1}, respectively) during 1973–2000. The comparison treatments (NP, PK, and NK) and the control (not fertilized) were selected for calculating nutrient efficiency. Rice grain yield increased at a 17.78 kg ha^{? 1} yr^{? 1} in the control, mainly due to development of improved cultivars. Phosphorus management was found to be important for indigenous fertility and rice productivity in this paddy soil. Yield increased significantly with P fertilization. Without N fertilization (PK), rice productivity increased 56.85 kg ha^{? 1} yr^{? 1} from 62% of NPK at the initial stage to 74% after passing 34 years, which might be affected by increasing biological N fixation with P accumulation in soil. In NK treatment, rice yield increased at a relatively low rate (37.82 kg hr^{? 1} yr^{? 1}) from the same rice productivity with that of NPK in 1967 to 91% after 34 years. In comparison, yield increased at a high rate (62.82 kg hr^{? 1} yr^{? 1}) without K fertilization (NP) from ca. 90% of NPK and might exceed the yield of NPK after 64 years of long-term fertilization. Therefore, K fertilization level might be readjusted after long-term fertilizing in paddy soil.     

Response of Wheat Cultivars to Nitrogen and Sulfur for Crop Yield,Nitrogen Use Efficiency,and Protein Quality in the Semiarid Region

ABSTRACT

The effects of nitrogen (N at 0, 100 and 180 kg N ha-1) and sulfur (S at 0, 20, 40 and 60 kg S ha-1) on crop yield, nutrient uptake, nitrogen use efficiency (NUE), and amino acid composition of two bread wheat cultivars, ‘Shehan’ and ‘Enkoy,’ grown in Andisols and Cambisols in randomized blocks with three replications were evaluated. Both cultivars responded significantly (P < 0.05) to N and S applications and S application with N improved the NUE by 28%. The yield increase for the two cultivars by N and S application ranged between 0.8 to 2.4 Mg ha^?1. The N concentration increased significantly from N0 to N2 in both cultivars. Sulfur fertilization increased the concentration of cysteine and methionine by 27% and 14%, respectively, as compared to N alone. The grain yield, NUE, N, and S uptake, and the S-amino acid concentration of ‘Enkoy’ were significantly higher than ‘Shehan’ cultivar.