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Sugarcane (Saccharum officinarum) is an important crop grown for the production of sugar, ethanol, and other by-products. The cultivation cycle from planting until harvesting usually takes at least a year, during which the plant is exposed to various environmental stress conditions. To improve tolerance to such stressful conditions, sugarcane plants can be treated with biostimulants, such as extracts from the brown seaweed Ascophyllum nodosum. Whether the application of such a biostimulant, alone or in combination with nutrients, improves stress resistance in sugarcane is unknown. In this study, we conducted two field trials: one in a cane-plant field and one in a ratoon field, with treatments applied to leaves during the fall (before the dry season) or spring (positive water balance in the soil). The treatments consisted of foliar application of nitrogen, potassium, boron, and zinc, provided alone (nutrient treatment) or together with A. nodosum extract (biostimulant treatment) and a control treatment (without foliar application). Overall, foliar application of biostimulant increased sugarcane stalk yield by 24 Mg ha−1 and sucrose yield by 4 Mg Pol ha−1 compared to nutrient treatment. In addition, agronomic efficiency and nutrient accumulation were higher in plants under biostimulant treatment compared to nutrient and control treatments. Therefore, the foliar application of A. nodosum extracts to sugarcane leaves is a promising strategy for improving drought tolerance, yield, and the nutritional status of the stalk.

Objective: To evaluate if there is an increase in the concentration of sugars in sugarcane grinding stalks as a result of controlled water stress. Design/Methodology/Approach: An experimental plot on cultivar MEX 69-290 was established in 2nd ratoon cycle, on a mollic Gleysol soil in the supply area of the Pujiltic sugar mill. Five treatments in irrigation suspension were established: T1=15 days; T2=30 days; T3=45 days; T4=60 days, and T5=75 days of suspension. The treatments were distributed in the field in a gradient plot design, following the slope of the land, with four repetitions within each irrigation strip. Results: The results show that suspending irrigation between 45 and 60 days before harvest increases the quality of the juices as well as the yields of the grinding stalks. In addition, natural precipitation plus irrigation water do not satisfy the water needs of the crop in the area under the scheme followed by the farmers. Study Limitations/Implications: Irrigation rotation. Findings/Conclusions: The authors recommend providing the necessary amount of auxiliary irrigation to satisfy the water demand of the crop during the growth cycle but suspending irrigation at the beginning of the ripening and maturity stage. [ABSTRACT FROM AUTHOR]

Copyright of Anadolu Tarım Bilimleri Dergisi is the property of Ondokuz Mayis Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Management strategies that reduce machinery traffic, such as creating seedbeds, could be adopted to preserve soil health and reduce soil physical restriction to sugarcane (Saccharum sp.) growth. Field experiments on clayey and sandy loam soils were conducted along four crop seasons (2013–2017) to investigate the changes in bulk density, soil penetration resistance, macroporosity and microporosity in the row and inter‐row positions, as well as sugarcane biomass production (root and stalk yield) under different machinery traffic treatments. The experimental areas were conducted in randomized block design with two treatments and four repetitions. The evaluated treatments were: (a) regular traffic, in which all operations were performed mechanically using regular machinery traffic; and (b) without traffic, in which all field operations (except those used for sunn hemp management and for opening the sugarcane planting furrow) were performed manually without machinery traffic. No critical values of physical properties were identified in either soil type in plots without machinery traffic, indicating the lowest density and soil penetration resistance values, as well as higher macroporosity, where sugarcane seedbed zones had been established. Our findings show that seedbeds resulted in greater root growth and development in the soil profile, mainly in inter‐row positions. Overall, sugarcane stalk yield was similar between the treatments in both soil types. This study reinforces the importance of the planting furrow in keeping suitable soil conditions for plant growth and concludes that sugarcane production in untrafficked seedbeds is an effective strategy to sustain soil physical conditions over the crop cycle, without the need for tillage operations during the (re)planting period. Highlights: The use of seedbeds sustains soil physical quality along the crop cycleMost of root biomass were concentrated in the crop‐rowCrop‐row position provides adequate soil physical conditions for root growth and plant developmentUntrafficked furrowed seedbed sustains soil physical quality and makes no‐tillage viable [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to evaluate rates and methods of potassium application for plant cane (Saccharum spp.) grown in a dystrophic Typic Haplustox with a sandy loam texture in the Brazilian Cerrado. The experiment was carried out in the municipality of Aporé, in the state of Goiás, using the RB92579 sugarcane variety. The experimental design was randomized complete blocks, with three replicates, in a 5x3 factorial arrangement, with five potassium rates (0, 60, 110, 160, and 200 kg ha-1 K2O as potassium chloride) and three application methods (100% at the bottom of the planting furrow and covered with soil, 100% side-dressed on the sugarcane rows 60 days after planting, and 50% in the planting furrow and 50% side-dressed). The amount of potassium in the stalks in the control treatment was greater than that of the potassium stock extractable by Mehlich-1 in the 0-60 cm soil layer. Stalk and sugar yields increase linearly with potassium rates, approximately 20% with 200 kg ha-1 K2O compared with the control treatment (without potassium). Potassium content in stalks also increases with potassium rates. There is no significant effect of the potassium application methods on stalk and sugar yields and on cane quality variables.

This study was laid out during the years of 2015–2016 and 2016–2017 at the village Niyamatpur Thakuran, Farrukhabad, India. The soil of the experiment site was sandy loam which is conducive for cane cultivation. The six treatment combinations, i.e. ratoon cane alone, cane ratoon + vegetable pea, cane ratoon + cauliflower, cane ratoon + cabbage, cane ratoon + radish and cane ratoon + onion, were tested on farmers' fields. Sugarcane planted in the spring season was harvested from the end of October to mid-November for juice and other purposes, and autumn ratoon was allowed. The row-to-row distance of cane ratoon was 90 cm; therefore, two rows of cauliflower and cabbage, three rows of radish and vegetable pea and four rows of onion were planted between two rows of autumn cane ratoon for fetching market value. The companion crops gave additional yield to the extent of 221 q/ha cauliflower, 319 q/ha cabbage, 224 q/ha radish, 118 q/ha green pods of vegetable pea and 298 q/ha bulbs of onion without any adverse effect on autumn ratoon. The highest stalk yield was weighed by 641 q/ha under companion cropping of cane ratoon + vegetable pea followed by cane ratoon + onion (639 q/ha). The lowest yield of cane ratoon was noticed in cane ratoon alone by 561 q/ha in comparison with all other companion cropping systems. The highest net return was computed under cane ratoon + onion cropping system (Rs. 38,794/ha) followed by cane ratoon + radish (Rs. 324,869/ha) and cane ratoon + vegetable pea for green pods (Rs. 32,236/ha). The similar trend was noted under benefit–cost ratio. [ABSTRACT FROM AUTHOR]

Sugarcane straw is a crop residue that has a dual purpose and can be maintained on the fields or used to produce bioenergy. The straw retention in the field provides multiple ecosystem services, and the complex interactions between straw and yield responses are hard to predict by local studies. The aim of this study was to investigate the straw removal effects on sugarcane yield in south-central Brazil. To achieve the objective, a set of 21 field studies was conducted in contrasting edaphoclimatic conditions. In addition, data of seven studies from the literature were included to build a more robust dataset. Since straw removal treatments were not homogeneous in all experiments, they were grouped as follows: NR, no removal (baseline treatment); LR, low removal; MR, moderate removal; and TR, total removal. To facilitate the data analysis, the experiments were gathered in four macroregions: southern Goiás, western São Paulo, central-eastern São Paulo, and northeastern São Paulo. The site location was the most effective individual factor to explain the straw removal effects on sugarcane yields. Compared with NR treatment, the average yield losses induced by LR, MR, and TR were 2, 10, and 13 Mg ha−1 in southern Goiás and 2, 4, and 6 Mg ha−1 in western São Paulo states, respectively. In other regions, no clear pattern was observed, and only site-specific effects were observed. Straw removal affected sugarcane yields in all soil types, but higher responses were observed under best conditions for sugarcane growth (i.e., clayey soils in southern Goiás). Our findings indicated harvesting season has a relevant role on determining yield responses to straw removal and younger ratoons are more responsive to straw removal. Conclusions from this study suggest straw removal recommendations cannot be designed based on isolated factors but require holistic and integrated knowledge to ensure that the straw amount left on field is enough to sustain multiple soil ecosystem services and crop yields. [ABSTRACT FROM AUTHOR]

Industrial use of sugarcane straw for bioenergy production represents a promising opportunity for the Brazilian sugarcane sector. Nonetheless, intensified straw removal may aggravate the effects of mechanized harvesting and increase the risks of soil compaction, declining sugarcane yield. An experiment was designed, and four field studies were conducted to evaluate the cumulative effects of straw removal on soil physical attributes (bulk density, BD; soil resistance to penetration, SRP; macroporosity, MaP; microporosity, MiP, and mean weight diameter of soil aggregates, MWD) and their relationship with crop yield under clayey and sandy soils in the São Paulo state, Brazil. In each field study, four straw removal rates (no removal, NR; low removal, LR, removal of 5 Mg ha−1; high removal, HR, removal of 10 Mg ha−1; and total removal, TR, removal of 15 Mg ha−1) were arranged in a randomized block design with four replicates. The 4-year intensive management of straw removal (HR and TR) resulted in an increased soil compaction (BD and SRP values) and reduced the MWD in both sandy and clayey soils. Our findings also showed that these effects are more significant in sandy soils, where soil carbon content was substantially reduced in HR and TR treatments. Sites with higher BD and SRP induced by straw removal were strongly associated with lower sugarcane yields, especially in sandy soils. Conversely, our findings indicate that LR was not detrimental to soil physical quality and sugarcane yield. Nevertheless, considering the multifunctionality of straw in sustaining multiple ecosystem services in different soil types, straw management should be defined taking into consideration site-specific conditions. We advocate that recommendations for straw removal should also be combined with other conservationist soil management practices in order to minimize soil compaction and its negative implications on sugarcane yield and other ecosystem services. [ABSTRACT FROM AUTHOR]

Nitrogen fertilization is essential to raise sugarcane yield in soils deficient in N. The objective of this study was to evaluate the effect of nitrogen application in production and borer attack on sugarcane. The experiment was conducted at Escobar District, State of Paraguarí, Paraguay. Three sugarcane growing seasons were evaluated during 2011-2013. The experimental design was randomized blocks with seven treatments and three repetitions, with annual application of increasing of nitrogen (0, 30, 60, 90, 120, 150 and 180 kg ha-1). At 360 days of each crop cycle, harvest was performed with the following assessments: industrial plant height, number of internodes per plant, infestation intensity index and yield. The nitrogen rate of maximum technical efficiency and maximum economic efficiency was determined. Statistical analysis of variance, means comparison and regression were performed. Nitrogen fertilization did not affect plant height and number of internodes, but increased yield and borer attack. For every kg ha-1 of nitrogen applied 0.25 t ha-1 of yield is added, and 0.27 % of infestation intensity index increase is obtained. The rate of maximum technical efficiency was 157,4 kg N ha-1 for a yield of 73,6 t ha-1, and the rate of maximum economic efficiency was 136.5 kg N ha-1 for a yield of 88,2 t ha-1.

Highlights • Leaf stripping and storm damage lead to the failure of deterministic modeling. • Data assimilation improves the modeling accuracy under interfered LAI. • The prediction and diagnosis performance rely on assimilation method. • The contribution of SWC and LAI to yield estimation depends on water stress level. Abstract Uncertainty in sugarcane (Saccharum officinarum (L.)) growth modeling is caused by a poor description of events such as artificial leaf stripping and natural storms. Data assimilation methods provide an effective strategy to integrate various measurements into crop models, rendering them less susceptible to model uncertainties. The objective of this study is to investigate the ability of three data assimilation methods to cope with interfered leaf area index (LAI), estimate stalk yield, and diagnose water stress. Through a two-year sugarcane field experiment, the data contribution to sugarcane soil-plant-atmosphere continuum simulation was quantified by assimilating soil water content (SWC) and LAI observations. Results demonstrated the importance of choosing appropriate data assimilation strategies. The forcing method failed to accurately simulate the temporal evolution of the soil moisture profile due to soil parameters not being updated, and the calibration method led to underestimated LAI before defoliation and overestimated LAI after defoliation. The EnKF method performed the best in estimating soil water content, LAI development, and sugarcane yield, as it reconciled simulation and observation uncertainties. The relative contribution of LAI and SWC data to yield estimation was dependent on water stress level. A reasonable diagnosis of water stress and subsequent impacts relies on the choice of data assimilation method. The forcing method is prone to producing high spatial variability of daily dry matter increase, and overestimated LAI from the calibration method after defoliation may lead to exacerbated and biased water stress estimates. [ABSTRACT FROM AUTHOR]

Sugarcane is the most promising among renewable biofuel-producing crops. An adequate availability of water and nutrients, especially nitrogen (N), is of utmost importance. From the hypothesis that the source and the rate of N fertilization influence the N use efficiency of an irrigated soil–sugarcane system, this study aimed to evaluate the stalk and crop residues (pointer and leaves) yield, as well as the N utilization, from different rates of ammonium nitrate and urea by irrigated sugarcane in the cane plant cycle, using an 15N isotopic dilution technique. The soil used for the experiment was an Oxisol (Rhodic Haplustox) Cerrado (savannah) phase. The experiment was carried out at a farm of the Raízen Mill, which was located in the municipality of Jataí, Goias State, Brazil. The sugarcane variety IACSP95–5000 was used in a randomized block design, with three replicates, four N rates (30, 60, 120, and 180 kg ha−1), and two fertilizer sources labeled with 15N isotopes (urea and ammonium nitrate). The average value for N utilization was 60.17% for the ammonium nitrate source and 44.95% for urea. The responses in the percentage and quantity of N in the sugarcane from the fertilizer increase with the increasing N rate. The soil was the main N source for sugarcane. The higher stalk and pointer yield was recorded at the average rate of 143.61 kg N ha−1. Further studies are needed to evaluate the residual effect of N in the next cycles.

Despite many losses, nitrogen may remain in the soil for more than one cycle. It can benefit the culture of sugarcane due to its longevity. The objectives of this study were to evaluate the yield of stalks and the recovery of residual N from urea applied to sugarcane (plant-cane cycle), which could be used by sugarcane ratoon subjected to different levels of water replacement and residual nitrogen doses. The experiment was conducted at an experimental area belonging to the Federal Institute Goiano, campus Rio Verde, Brazil, using plastic pots containing dystrophic Red Latosol from Cerrado and cattle manure. The experimental design was completely randomized with three replications analyzed in 3 × 3 split plots. The treatments consisted of three levels of water replacement (75, 50 and 25% of field capacity) and three residual N doses (60, 120 and 180 kg ha−1) in the form of urea enriched with 15N applied to plant-cane in a preceding cycle. Residual N doses influenced the stalk yield. The highest stalk yields was achieved by high water replacements. The nitrogen recovery was high in the residual N dose of 60 kg ha−1 initially applied to plant-cane when associated with water replacement at 75%. Regardless of the N dose applied, the use of residual N was less than 7.06% of the amount originally applied to plant-cane. [ABSTRACT FROM AUTHOR]

O Brasil é o maior produtor mundial de cana-de-açúcar e, devido à crescente demanda por fontes renováveis de energia, a área cultivada encontra-se em expansão. Regularmente, a cultura é plantada em solos com baixos teores de nutrientes, o que pode limitar sua produtividade. A adubação potássica da cana-de-açúcar é feita basicamente no sulco de plantio, o que pode comprometer a eficiência de utilização desse nutriente devido a possíveis perdas por lixiviação ou salinidade às raízes das plantas. O objetivo deste estudo foi avaliar produtividade de colmos e atributos tecnológicos da cana-de-açúcar em função de doses e modos de aplicação de K. O experimento foi conduzido em um Latossolo Vermelho distrófico durante o ciclo de cana-planta, com o cultivar SP90 3414, em esquema fatorial 2 x 4, sendo dois modos de aplicação (100 % no plantio e 50 % no plantio + 50 % em cobertura) e quatro doses de K (0, 100, 150 e 200 kg ha-1 de K2O), com quatro repetições. Aos nove meses após o plantio, foram avaliados a altura das plantas e o perfilhamento e, na colheita, a produtividade de colmos e os atributos tecnológicos da cana-de-açúcar. As doses de K aumentaram o crescimento em altura e o perfilhamento da cana-de-açúcar, para os dois modos de aplicação; a produtividade de colmos e de açúcar aumentou com as doses de K até um ponto de máximo de, aproximadamente, 160 kg ha-1 de K2O; e a produtividade máxima estimada de cerca de 160 t ha-1 foi obtida com 130 e 150 kg ha-1 de K2O, para a aplicação parcelada e única do fertilizante, respectivamente.Brazil is the largest sugar cane producer in the world and, due to the increasing interest in renewable energy sources, the cultivated area is expanding. Sugar cane is usually planted in soil with low nutrient levels, which can limit the yield. In sugar cane, potassium is basically applied in the furrow, which can decrease the K use efficiency due to leaching or salinizaton to plant roots. The goal of this study was to evaluate stalk yield and technological properties of sugar cane as related to K application rates and methods. The experiment was carried out in an Oxissol during a plant cane cycle of variety SP90 3414, in a 2 x 4 split-plot design, with two K application methods (a - 100 % in the planting and b - 50 % in the planting and 50 % side-dressed after six months) and four K rates (control, 100, 150 and 200 kg ha-1 K2O), with four replications. Nine months after planting, plant height and shoot number were evaluated and, in the harvest, stalk yield and technological properties were obtained. The K rates increased sugarcane growth and shoot number in both application methods; the stalks and sugar yield increased with potassium rates, reaching a peak at a dose of around 160 kg ha-1 K2O; the estimated maximum yield (160 t ha-1) was obtained with 130 kg ha-1 of K2O in split application (in the furrow and side-dressed after six months) and with 150 kg ha-1 of K2O when the fertilizer was applied in the furrow only.

Two field experiments were conducted at Agriculture Faculty farm of Demo (29°17 N; 30°53 E) El-Fayoum University, Egypt, during 2013 and 2014 to study the effect of three nitrogen rates, i.e. 80, 100 and 120 kg N/fed. on the damage cause by pink stem borer infestation [Sesamia cretica Lederer (Lepidoptera: Noctuidae)] under natural infestation, on stem characteristics, quality and yield traits. In addition to theoretical ethanol production of two sweet sorghum varieties (Brandes and Honey). Data obtained revealed that: Brandes variety is more tolerant to pink stem borer attack which recorded less damage sings measured in this study by many damage expressions. Moreover, Brandes exhibited better productivity traits (stalk, juice, syrup, grain, forage and ethanol yields) as well as quality traits (TSS, sucrose, reducing sugars, Total fermentable sugars and purity). The results also showed that application of the highest nitrogen rate (120 kg N/fed.) increased all borer infestation features, productivity and quality traits. The interaction between both variables markedly affected most studied traits, but in general, Brandes variety fertilized by the highest N rate exhibited the higher productivity and quality traits and the lower damage signs or to some extend characterized as moderate tolerance to pink borer infestation. [ABSTRACT FROM AUTHOR]

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two field experiments were carried out at the Research Experimental Farm of Sabahia Agricultural Research Station in Alexandria during the two successive growing seasons of 2011/ 12 and 2012/ 13. G2006-77 sugarcane variety (Saccharum officinarum L) was cultivated to investigate the effect of irrigation regime and nitrogen fertilizer level and their interaction on sugarcane yield and its components. Main plots were represented by three irrigation regime:1- (large interval) 18 irrigations/year was given to first treatment irrigation at (15 days interval in Summer, 20 days interval in Spring and Autumn and 30 days interval in Winter seasons), 2-(middle interval) 25 irrigations / year was given to second treatment irrigation at (10 days interval in Summer, 15 days interval in Spring and Autumn and 21 days interval in Winter seasons) and 3- (short interval) 32 irrigations / year was given to third treatment irrigation at (7 days interval in Summer, 13 days interval in Spring and Autumn and 15 days interval in Winter seasons,). The sub plots were used for the three nitrogen levels (140, 200 and 260 kg N / Fed). The results indicated that: The second regime middle irrigation intervals was insignificantly increased stalk length, stalk diameter, stalk yield, sugar yields, T.S.S (%), sucrose (%) and purity (%) compare with the first and third regime through the two successive seasons. Increasing applied N levels from 140 up to 200 Kg N /fed. significantly increased stalk length, stalk diameter, stalk yield, sugar yields T.S.S (%), sucrose (%) and purity (%). The interaction between irrigation intervals and nitrogen levels on the studied traits were not significant except sucrose (%) in the two seasons. [ABSTRACT FROM AUTHOR]

The sweet sorghum variety, ICSV 93046 is commercially cultivated in large areas in India and the Philippines. The response of ICSV 93046 to six fertilizer treatments viz., T1 (control: 80 kg N ha and 40 kg PO ha); T2 (designed fertilizer from a commercial source); T3 (N + P with Zn and B soil application); T4 (N + P with Zn and B soil application); T5 (N + P with foliar application of 0.1 % sodium borate and T6 (N + P with foliar application of 0.5 % ZnSO and 0.1 % sodium borate) was evaluated during the post-rainy season (December-March, 2009-2010) as main (plant) crop and during summer season (April-July, 2010) as ratoon crop. The combined ANOVA showed that there were no significant differences observed between main and ratoon crops and the treatment interactions for the qualitative and quantitative component traits of sugar yield measured and also no significant differences observed for main and ratoon crop except for non-significant numerical differences giving a trend. The stalk yield was highest for treatments T5 and T6 in main crop and in the ratoon crop however, the treatment T4 recorded the highest stalk yield. [ABSTRACT FROM AUTHOR]

Understanding the responses of sweet sorghum to flooding and the characters associated with flooding tolerance may be a useful strategy for pre-rice production and help meet demand for biofuel feedstock. Three sweet sorghum genotypes (Bailey, Keller and Wray) and five flooding treatments including non-flooding control, continuous flooding extended from 30, 45, 60 and 75 days after emergence to harvest were conducted under greenhouse conditions. Flooding decreased leaf dry weight (22-60%), leaf area (10-70%), number of node per stalk (1-5%), shoot dry weight (5-20%) and stalk yield (2-22%) with highest reduction in 30 days after emergence flooding treatment. Flooding later than 30 days after emergence did not significantly affect shoot growth, yield and yield components. Brix value, sucrose content and total sugar content were not significantly affected. All studied cultivars had similar shoot growth response. Flooding induced development of roots in water; root length, root dry weight, nodal root and lateral root number and interconnection of aerenchyma spaces from roots in flooded soil to stalk base above water level but suppressed root growth in flooded soil. The acclimation traits were highest in Keller, flooding from 30 days after emergence but there was a lack of root development in 75 days after emergence flooding treatments. These findings indicate the effect of waterlogging on sweet sorghum growth and yield strongly depends on the growth stage at which it occurs. There were genetic variations in root morphological and anatomical responses to flooding of sweet sorghum. The development of nodal and lateral roots and aerenchyma formation from flooded plant parts to stalk bases above water level may distribute to flooding tolerance in sweet sorghum. Based on the results, a flood-free period of at least 30 days after emergence is required to sustain yield of pre-rice sweet sorghum and early planting is highly recommended. [ABSTRACT FROM AUTHOR]

Abstract: Kenaf is an important fiber crop worldwide. It was recently introduced to South Africa as a commercial fiber crop. The aim of this study was to determine how different environments and seasons influence stalk yield. Nine kenaf cultivars from various countries were analysed in two environments, over two consecutive seasons, where one location was irrigated and the other not. Data were recorded for total fresh yield, defoliated stalk yield and dry stalk yield. Yield stability was analysed with four different statistical models. The dry stalk yield varied from 15.33 to 17.78ton/ha. El Salvador and Tainung 2 had high dry stalk yields in the favourable environments, but Tainung 2 did not have stable yield across all trials. Everglades 41 and El Salvador were the most stable of the varieties across both environments and seasons. El Salvador was the cultivar that had the highest and most stable dry stalk yield in the two seasons and two locations in South Africa, and should perform well in commercial production. [Copyright &y& Elsevier]

Sugarcane is the most promising among renewable biofuel-producing crops. An adequate availability of water and nutrients, especially nitrogen (N), is of utmost importance. From the hypothesis that the source and the rate of N fertilization influence the N use efficiency of an irrigated soil–sugarcane system, this study aimed to evaluate the stalk and crop residues (pointer and leaves) yield, as well as the N utilization, from different rates of ammonium nitrate and urea by irrigated sugarcane in the cane plant cycle, using an 15N isotopic dilution technique. The soil used for the experiment was an Oxisol (Rhodic Haplustox) Cerrado (savannah) phase. The experiment was carried out at a farm of the Raízen Mill, which was located in the municipality of Jataí, Goias State, Brazil. The sugarcane variety IACSP95–5000 was used in a randomized block design, with three replicates, four N rates (30, 60, 120, and 180 kg ha−1), and two fertilizer sources labeled with 15N isotopes (urea and ammonium nitrate). The average value for N utilization was 60.17% for the ammonium nitrate source and 44.95% for urea. The responses in the percentage and quantity of N in the sugarcane from the fertilizer increase with the increasing N rate. The soil was the main N source for sugarcane. The higher stalk and pointer yield was recorded at the average rate of 143.61 kg N ha−1. Further studies are needed to evaluate the residual effect of N in the next cycles. [ABSTRACT FROM AUTHOR]