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Ensuring food and nutritional security in light of high climate variability and a rapidly growing population remains a challenge. Mungbean (Vigna radiata (L.) Wilczek) is a short duration, drought-tolerant, and ureide-exporting legume crop capable of symbiotic atmospheric nitrogen fixation. Estimates of biological N2 fixation by mungbean in different soil textures have not been extensively studied. We conducted this study to evaluate plant growth and N2 fixation of five mungbean genotypes (Berken, 8735, IC 8972-1, STB#122, 223) inoculated with Bradyrhizobium spp. and grown on loamy sand and silt loam soils under glasshouse conditions. Mungbean dry matter yield, δ15N values, shoot content, amounts of N-fixed, and soil N uptake were all higher on the silt loam soil compared to the loamy sand soil, demonstrating the effects of soil properties on plant growth and N2 fixation potential. Among genotypes, IC 8972-1 produced the highest biomass (7.85 g plant−1), shoot N content (200 mg plant−1), and soil N uptake (155 mg plant−1) than other genotypes. The significant interaction between soil texture and genotypes for root dry matter and %Ndfa indicates the major role of legume root-nodule bacteria in symbiotic N2 fixation. This study demonstrated that N2 fixation in mungbean is affected by both genotypes and soil properties, illustrating the need to consider soil properties in order to maximize N contribution from mungbean to agricultural production systems.

In Senegal, sweet corn is produced for export market while the canned ones are imported to supply national market. This work was carried out to investigate the effect of different processing conditions such as heating temperature and sterilization time on the microbial quality, color, ascorbic acid and shelf life of canned sweet corn produced in Senegal. The hygiene level of sweet corn samples at different preliminary processing stages before canning processing was evaluated also. Aerobic mesophilic total counts were lowest at blanching (1.8 log10 CFU/g) and no microorganisms related to food spoilage and public health concerns were detected in all canned sweet corn regardless of treatment. However, treatment E (125°C/12 min) had the highest F-value (35.7 min) and the lowest C-value/F-value ratio (3.84 min). This treatment had also less impact on total color change (DE*=6.81) and ascorbic acid content. Canned sweet corn was shelf stable after 12 months of storage. Key words: Sweet corn processing, canning processing, sterilization, thermal treatment, microbial quality, shelf life, color, vitamin C.

Both Israel Finkelstein and William Dever have allegedly distanced themselves from the kind of “biblical archaeology” of William F. Albright. Their own efforts, however, to relate Palestinian archaeology and biblical narrative not only reflect Albright’s earlier methods, they create a politically oriented incoherence. In three recent works, since the turn of the millennia, Finkelstein uses archaeologically based arguments primarily to resolve problems of biblical interpretation. Dever, who also has published three biblical-archaeological studies since 2001, concentrates, rather, on archaeological issues, while using biblical narrative for his underlying historical context. A discussion of the figures of Solomon and Josiah on the one hand and a discussion of “landscapearchaeology” and site classification, on the other hand, illustrate theshortcomings of their methodology.

Artiklen opstiller tre hypoteser om teksterne i Det Gamle Testamente: De er bestemt af en teologisk traditionskritik, de tilhører et relativt sent diskursivt felt (fra hellenistisk tid), og dette felt har været afgørende for de traditioner som blev traderet

This article is presented in the hope of engaging debate on Palestine's cultural heritage in view of recommending a revision of the Palestinian high-school curriculum for the pre-Islamic history of Palestine. After a brief clarification of intent and an introduction to the current status of research on Palestine's history, brief summaries of the proposed curriculum are offered in chronological order: 1) the Stone Age; 2) the Bronze Age; 3) regional histories from Iron I to Alexander and 4) the Hellenistic Period. The presentation closes with a conclusion, followed by 3 appendices on early legendary figures in Palestinian history; on Palestinian place names and on the importance of structuring Palestine's history regionally.

The article argues, in continuation of previous contri-butions by the author, that “Judaism”/”Jews” are from the outset ideological and religious constructs rather than ethnic entities. As-syrian Judaa and Persian Yehud were geographical and political designations limited to the Southern highland of Palestine and it is unlikely that the extensive references to yehudim known from the Hellenistic period onwards should in all cases cover people origi-nating from that particular area. The origins of Judaism should not be sought in any invariable ethnic quality of the various populations of Palestine in antiquity but in the influence and shaping of reli-gious ideologies with the holy city of Jerusalem as a strong and cen-tral symbol.

Located within the Sahel region, Senegal faces several agricultural production challenges. Limited rainfall, poor soil fertility, and insufficient agronomic inputs all contribute to low pearl millet [Pennisetum glaucum (L.) R. Br.] yields. This study was initiated to assess the potential for increasing millet yields through intercropping (living cover) and mulching (desiccated cover) practices. During the 2013 and 2014 growing seasons, pearl millet was intercropped with cowpea [Vigna unguiculata (L.) Walp.], mungbean [Vigna radiata (L.) Wilczek], or grown under mulch (neem [Azadirachta indica] leaves applied at 2 t ha–1). Field trials were conducted at two sites within Senegal’s central millet– peanut (Arachis hypogaea L.) basin, in Bambey (14°41¢382 N, 16°28¢122 W) and iés (14°45¢452 N, 16°53¢142 W). Soil moisture and plant N (based on the normalized difference vegetation index [NDVI]) were measured in addition to yield. When inter- cropped with a legume, millet grain yields increased up to 55% compared to millet alone. The combined grain yields under inter-cropping (millet + legume) were always higher than yields of millet alone, up to 67% in Bambey. Mulching increased soil moisture up to 14%, with yield increases of up to 70% over millet with no mulch. Plant N increased in both intercropped and mulched millet, with NDVI increases up to 21% with mulch and 16% when grown with a legume (prior to flowering). These yield increases were achieved using resources that are available and affordable to small-scale producers in the region (seeds and mulch), and did not require the addition of fertilizer input. Published version

Cover crops are a major focus of conservation agriculture efforts because they can provide soil cover and increase nutrient availability after their mineralization in cropping systems. To evaluate the effect of residue type and placement on rate of decomposition and carbon (C) and nitrogen (N) mineralization, residues from two food crops, maize (Zea mays L.) and common bean (Phaseolus vulgaris L.), and two promising cover crops, sunn hemp (Crotalaria juncea L.) and sorghum sudangrass (Sorghum bicolor [L.] Moench x S. bicolor var. Sudanese [Piper] Stapf) were used in a litterbag study in the Central Plateau region of Haiti from May to September, 2013. Residues were placed in litterbags at a rate equivalent to 3.25 Mg residue ha(-1) either on the soil surface or buried at 15 cm to represent a tilled and no-tillage system, respectively. Initial C:N ratios were: maize common bean sorghum sudangrass sunn hemp. Highest residue mass loss rates and C and N mineralization generally occurred in the reverse order. Overall, surface-placed residues decomposed more slowly with 40 and 17 % of initial residue mass of surface and buried residues, respectively, remaining at 112 days. Carbon and N mineralization was higher when residues were buried. Net N mineralization of buried residues was 0.12, 0.07, 0.06, and 0.03 g N g residue(-1) for sunn hemp, sorghum sudangrass, maize, and common bean, respectively over 112 days. To achieve the goal of increasing nutrient supply while maintaining year-round cover, a combination of grass and legume cover crops may be required with benefits increasing over multiple seasons.

Taking my point of departure in questions of ethnogenesis within the regions of Yehud and Idumea in the pre-Hasmonean period, I analyze the interrelationship of the themes of conflict and reconciliation in the composition of Genesis. I pay particular attention to perceptions of Idumea in narrative reiterations which tie the Cain story to the narratives about the destruction of Sodom and the Jacob-Esau conflict story in order to raise the question of whether the narrative strategy reflected in these stories might justify a further analysis of the Jacob and Joseph stories as contributions to a larger mnemonic discourse, bearing a utopian trajectory aimed at a realization of Ezekiel 16's reconciliation between Idumea, Yehud and Samaria.

During the last several decades, members of the SSSA have discussed several trends related to soil science education, including: (i) declining academic programs and course offerings at land grant universities, (ii) decreased enrollments, and (iii) improved employment opportunities for soil science graduates (SSSA, 2006; Ferris et al., 2010). The SSSA Advocacy/Education Task Force met in 2007 and concluded that quantitative survey information was needed to document trends in soil science academic programs, student enrollment, faculty, and job opportunities for graduates. Suggested survey topics included: · Has the recognition of soil science as a distinct discipline increased or decreased? · How has the job market changed during the past decade, and how will job opportunities for soil scientists change in the future? · How have undergraduate and graduate soils curricula changed during the last decade? · Has enrollment in soil science degree programs and courses changed during the past decade? · Has there been a change in the degree programs of students enrolling in soils courses in the past decade? · Have soil science programs been combined with other programs? Therefore, the objective of the survey was to quantify trends in student enrollment, faculty positions, pertinent educational issues in soil and related sciences, and career or job opportunities and trends. Expected outcomes included a better understanding of current educational practices and trends, and identification of specific opportunities for SSSA to enhance the practice and profession of soil science.

Mungbean [Vigna radiata (L.) Wilczek] is a short-duration and relatively drought-tolerant crop grown predominantly in the tropics. This grain legume can improve soil fertility through biological nitrogen (N) fixation. To assess the effects of Bradyrhizobium (group I) inoculation on yield and yield attributes of mungbean, a greenhouse study was conducted during Fall 2016 with two mungbean cultivars (‘Berken’ and ‘OK2000’), two inoculum treatments (inoculated and uninoculated), and two soil textures (loamy sand and silt loam). Pots were laid out in a completely randomized design and treatment combinations were replicated seven times. The main effects of cultivar and soil texture significantly (P ≤ 0.05) affected mungbean seed weight and plant residue mass. Seed yield (13%), plant residue (22%), and protein content (6%) of OK2000 were significantly higher than Berken cultivar. A 31% seed yield and 40% plant residue increase were recorded on silt loam soil compared to loamy sand soil. Significant increase in plant height (18%) and number of pods per plant (21%) were also recorded when mungbean plants were grown on silt loam compared to loamy sand soil. Bradyrhizobium inoculation significantly increased the number of pods per plant, the number of seeds per plant, and seed yield. [Cultivar × inoculation] and [cultivar × soil texture] interactions had significant (P ≤ 0.05) effects on number of seeds per pods and plant height, respectively. Understanding the agronomic practices and soil physical properties that may limit mungbean production could help in optimizing its establishment and growth in non-traditional growing areas.

Moby Dick: Jonah, Ahab, and Ishmael Father Mapple’s sermon on Jonah in Moby-Dick is a biblical narrative in the form of a short story, allegorically structured as a parable on nationalist hatred and divine compassion. It takes its point of departure from the obscure figure of a pre-exilic prophet, borrowed from the brief story about the reign of Jeroboam II (2 Kings 14.23-29). Jeroboam was king in Samaria for forty-one years. He not only saved Israel from extinction, but also “restored” its utopian “Solomonic” borders (1 Kings 8.65) south to the Dead Sea and north as far as the great Syrian cities of Hamath and Damascus. Jeroboam’s great success is attributed to his obedience to the advice of the prophet, Jonah Ben Amittai, who was from the town of Gath ha-Hepher in the Lower Galilee. This prophet Jonah incited Jeroboam to a holy war with the ambition of bringing all of Yahweh’s land back to Israel.1 The Book of Jonah’s use of this figure—a classic biblical portrayal of the prophet of Yahweh’s judgment, ever zealous for Israel’s messianic victory over nations in uproar (Psalms 2.1-2)—offers a man who is eager to complete the great victories of 2 Kings by bringing Yahweh’s judgment to the heart of the empire itself. This Jonah wishes to be another Elijah in his zeal: a veritable Nahum, a prophet of doom to bring divine destruction on the great city of Nineveh (Nahum 1-3). The book opens as Yahweh tells Jonah that the news of the great evil of Assyria’s Nineveh has come to him (Jonah 1.2). This same motif is used in Genesis 18.21 when Yahweh tells Abraham about his plans to destroy the evil city of Sodom. Although in Genesis, Abraham had argued against Yahweh that the innocent not be destroyed with the guilty, in Jonah’s book, the prophet is no Abraham, one in whom all the nations of the world are to be blessed (Genesis 12.3). Jonah knows already that his Yahweh has become “a gracious God and merciful, slow to anger and abounding in

Sweet corn is an underutilized crop for human consumption in Senegal. In this study, physical and biochemical characterization were performed on four sweet corn ear varieties grown at three different fertilization rate of 15N-15-P-15K. Treatment F1 was 40 tons/Ha horse-dung + 200 kg/Ha of 15N-15P-15K, treatment F2 was 30 tons/Ha horse-dung + 150 kg/Ha of 15N-15P-15K) and treatment F3 was 50 tons/Ha horse-dung + 250 kg/Ha of 15N-15P-15K. Results showed that Yosemite cultivar gave the highest number of kernels/ear (672.3), followed respectively by Legacy (642), Excellis Garrison (585.6) and Infinity (573). Furthermore, treatments using fertilizer 3 (F3: 50 tons/Ha horse-dung + 250 kg/Ha of 15N-15P-15K) led to the highest number of kernels/ear in all cultivars used. Interestingly, Legacy cultivar gave more reducing sugars (5.1 ± 0.8 g.100g -1 ) with treatment F1; treatment F3 provided less reducing sugars (2.1 ± 0.6 g.100g -1 ) and more starch (14.4 ± 0.5 g.100g -1 ). Overall, physical and biochemical characteristics were influenced to at least some extent by fertilization treatments related to the cultivar used. Yosemite and Legacy cultivars would be more suitable for canned sweet corn production in the conditions studied. Sangalkam seems to be more suitable for sweet corn production.

Since the time of the British mandate, Zionist and, later, Israeli politics of nation-building has strongly influenced ‘biblical archaeology’ and has significantly undermined the integrity of Israeli scholarship. Critiques from Yael Zerubavel and Keith Whitelam to Nadia Abu El-Haj and Raz Kletter have repeatedly pointed out the consistent nationalistic distortions that have infected the field. The efforts of critical scholars to write a history of Palestine independent of biblical perspectives have corrected such distortions since the 1980s and have raised considerable doubt concerning the legitimacy of the Judeo-ethnocentrism which dominates nationalist Israeli claims on the heritage of ancient Palestine and the Bible.

Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation (SDI) provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics (i.e., paying for the SDI system), including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.

Three times Genesis presents mankind as created in the image of God: the known is explained with the help of the unknown, as this narrative takes place in Feuerbach’s hall of mirrors. Do these texts speak of humanity created in God’s image or of the divine created in likeness of the human? Certainly the figure of Yahweh which dominates the narrative of the Pentateuch, reflects some of the most repulsive and objectionable of human traits. Does the narrative of the Pentateuch present us with its authors’ image of God or does it use ironic inversion to ultimately agree with Job that the God it narrates is false: one won from rumors, stories and tradition: a misunderstanding of the divine; that is, precisely the god as Israel of the past knew him. Taking its point of departure in my inaugural lecture, which dealt with the expression of Yahweh’s self-understanding, presented in the story of Moses at the burning bush, the first part of the lecture takes up the motif of images and likenesses of Yahweh in the stories of the golden calf, the feeding of Israel with manna and quail in the wilderness and the sending of the spies to the Valley of Eshkol. With the help of these narratives, I can then turn to the three-fold allegory of humanity as created in the image of God in Genesis 1-11 to compare this narrative figure of Yahweh with the concept of God in the Book of Job.

Taking its point of departure in the expression of Yahweh's self-understanding as presented in the story of Moses at the burning bush, the first part of the lecture takes up the theme of representations of Yahweh and the narrator's presentation of Yahweh in the stories of the golden calf, the quail and the sending of the spies to the Valley of Eshkol in Exodus and Numbers. It then turns to the three-fold allegory of humanity as created in the image of God in Genesis 1–11, comparing this narrative figure of Yahweh with the concept of God in the Book of Job.

The global impact of an increased concentration of CO2 in the atmosphere on plants has been studied extensively, but little information has been published on the effect of enrichment of atmospheric CO2 on the nutritive value of grain and straw used as ruminant feeds. This paper reports the chemical composition and nutritive value of grain and straw harvested from the drought tolerant hard red spring wheat (Triticum aestivum L.) variety Yecora Rojo managed with two carbon dioxide regimes (ambient, 350 μl/l and elevated, 550 μl/l), two rates of nitrogen application (low N: 53 kg N/ha and high N: 393 kg N/ha) grown under a water-fed (i.e., no deficit) regime. Accumulation of carbon in straw did not differ among crops grown under elevated CO2 and low N supplementation and crops grown under ambient CO2 with low levels of N supplementation. Increased N application increased sequestration of C (P

In subsurface drip irrigation (SDI) systems, water constraints to cotton (Gossypium hirsutum L.) production are greatly minimized and N management becomes the main priority. Injecting N fertilizer into SDI systems should, in theory, be as efficient as the irrigation delivery system itself. The objective of this study was to test duration of N injections, addition of the nitrification inhibitor ammonium thiosulfate (ATS), and using canopy spectral reflectance to guide N injections in a 2-yr study of SDI cotton in Lubbock, TX. For a 1400 kg ha -1 expected lint yield, the N fertilizer rate was 170 kg N ha -1 minus the 0- to 0.6-m soil NO 3 -N and an estimate of irrigation water NO 3 (20 and 30 kg N ha -1 for 2005 and 2006). We tested injection of urea-NH 4 NO 3 (UAN) between first square and early bloom, and first square and peak bloom. There was no effect of timing or ATS on lint yield. Reflectance-based N management up to peak bloom resulted in savings of 28 and 17 kg UAN-N ha -1 for 2005 and 2006, respectively, compared with soil-test-based N fertigation. Lint yields were similar between reflectance-based UAN management (1814 kg ha -1 ) and UAN injected up to peak bloom based on soil test NO3 (1880 kg ha -1 ). Nitrogen fertilizer recovery at first open boll was not affected by treatment but was high (62-75%). Flux of N 2 O + N 2 was low (800-2100 g N ha -1 ) in both years and was not different between fertilized and unfertilized plots. Residual 0- to 1.2-m soil profile NO3 after 2 yr was not affected by N fertigation treatments. Nitrogen fertilizer injections in SDI cotton are utilized very efficiently, and spectral-reflectance-based approaches have potential to reduce N fertilizer inputs.

Salts that accumulate near the soil surface with subsurface drip irrigation (SDI) can hinder the establishment of succeeding direct-seeded crops. To prevent crop loss or yield reduction, producers rely on sprinklers for germination, which is often expensive and requires added capital inputs. Predicting salt movement and accumulation with SDI will allow producers to anticipate the need for sprinkler irrigation for salt control. The HYDRUS-2D model was used to model salt accumulation from an SDI system on successive crops of cantaloupe (Cucumis melo L. ssp. melo var. cantalupensis Naudin) and broccoli (Brassica oleracea L. var. italica Plenck) with two tape depths (18 and 25 cm), different germination practices (germination with SDI and with sprinklers), and water salinity (1.5 and 2.6 dS m -1 ). Predicted saturated-paste electrical conductivity (ECe) values from HYDRUS-2D were significantly correlated with actual ECe data obtained from field experiments (r 2 = 0.08-0.93). After Season 1, the correlation coefficients were highly variable, with the majority of model ECe values being higher than field data. Season 2 results indicated a much stronger relationship, with R 2 values as high as 0.93. Model predictions for Season 2 showed underprediction of ECe when compared with actual ECe. Relationships between model-predicted ECe and actual ECe resulted in a slope of nearly 1.0 for all treatments and a y intercept close to -1 dS m -1 . A better understanding of the processes that occur at the field scale, such as root growth, root distribution, and plant water uptake, is essential for modeling water and solute transport with SDI. A better characterization of evapotranspiration from SDI is required to accurately model salt accumulation.

Subsurface drip irrigation (SDI) can result in accumulation of soluble salts at or near the soil surface. In the southwestern USA, rainfall is usually inadequate for stand establishment, thus supplemental irrigation is necessary. Use of sprinklers to minimize salt concentrations near the soil surface is an alternative to using SDI for stand establishment. Our objective was to evaluate the effects of germination method (irrigation with SDI or sprinklers), depth of SDI tape (0.18 and 0.25 m), and irrigation water salinity (1.5 and 2.6 dS m-1) on salt and Br distribution after each of two consecutive growing seasons. Treatments consisted of factorial combinations of these three factors. Bromide was used to trace salt accumulation from the drip tape. After season 1, the highest salt concentrations (ECe up to 11 dS m-1) were in the top 3 cm of soil. Below 3 cm, soil EC dropped significantly and remained constant to 1.05 m. Similarly, Br concentrations were highest in the top 3 cm of soil. The mass of salt and Br recovered in the top 3 cm were significantly affected by tape depth, and water EC significantly affected salt mass. Salt present in the soil after season 1 adversely affected crop emergence in season 2, where SDI was used for stand establishment. After season 2, the highest salt and Br concentrations were at about 25 cm depth, probably due to ~210 mm of rainfall that occurred near the end of the growing season. There were no significant differences among treatments in the mass of either salt or Br in the top 3 cm or 16 cm of the soil profile after season 2. Timely rainfall, transplanting rather than direct seeding, and changing bed geometry can reduce dependence on sprinklers for stand establishment

Mining activities are a major source of land degradation in arid regions, and remediation methods developed for mesic sites may not be appropriate for arid sites. In climates where potential evapotranspiration exceeds precipitation, it might be possible to prevent the migration of contaminants away from a mine site by controlling the site water balance through vegetation, and allowing natural attenuation processes to reduce pollutant levels over time. We investigated the feasibility of remediating a nitrate-contaminated source-plume system in a desert environment using biological methods. The study site was a former uranium mill in Monument Valley, Arizona, where NO 3 − used in ore processing had leaked from the soil beneath a tailings pile (referred to as the source area) into an alluvial aquifer (referred to as the plume) spreading away from the source area. We used 15 N/ 14 N ratios and direct assays of denitrification to show that biological denitrification occurred in both the source area and plume, and could reduce NO 3 − levels over time. Denitrification in the source area could be stimulated by providing additional moisture to the soil through irrigation, whereas providing a carbon source (ethanol) stimulated denitrification in samples from the plume. We used 18 O/ 16 O and H/deuterium signatures in water and plant samples to show that the native saltbush ( Atriplex canescens ) and black greasewood ( Sarcobatus vermiculatus ) plant community was extracting water from the plume, offering a possible means of preventing migration of the plume by controlling grazing over the site. We conclude that biological remediation is a feasible alternative to pump/treat solutions at this type of site.

The impacts of increasing atmospheric CO 2 , an important greenhouse gas, on soil microbial production and consumption of other greenhouse gases such as N 2 O are uncertain. This study was conducted during the 1998 and 1999 summer growing seasons at the Free-Air CO 2 Enrichment (FACE) site in Maricopa, AZ. The objective was to measure N 2 O and denitrification emission rates in a C 4 sorghum [Sorghum bicolor (L.) Moench] production system with ample and limited flood irrigation rates under FACE (seasonal mean = 579 μmol mol -1 ) and control (seasonal mean = 396 μmol mol -1 ) CO 2 . Plots were sampled for N 2 O flux using both chamber and intact incubated soil core techniques. Nitrogen gas (N 2 O plus N 2 ) emissions were measured using intact incubated soil cores with C 2 H 2 inhibition. Nitrous oxide emissions measured with chambers increased markedly after irrigation and fertilization following prolonged periods without water under both elevated and control CO 2 conditions. Within 5 d of fertilization and irrigation, N 2 O emissions measured with chambers were 250 g N 2 O-N ha -1 d -1 . Seasonal cumulative N 2 O-N emissions measured using chambers were 500 g N 2 O-N ha -1 d -1 ) coming with >55% WFPS. Neither soil NO 3 - nor soil organic C alone limited N gas emissions. Elevated CO 2 did not result in increased N 2 O or N-gas emissions with either ample or limited irrigation.

Various remote sensing indices have been used to infer crop nitrogen (N) status for field-scale nutrient management. However, such indices may indicate erroneous N status if there is a decrease in crop canopy density influenced by other factors, such as water stress. The Canopy Chlorophyll Content Index (CCCI) is a two-dimensional remote sensing index that has been proposed for inferring cotton N status. The CCCI uses reflectances in the near-infrared (NIR) and red spectral regions to account for seasonal changes in canopy density, while reflectances in the NIR and far-red regions are used to detect relative changes in canopy chlorophyll, a surrogate for N content. The primary objective of this study was to evaluate the CCCI and several other remote sensing indices for detecting the N status for cotton during the growing season. A secondary objective was to evaluate the ability of the indices to appropriately detect N in the presence of variable water status. Remote sensing data were collected during the 1998 (day of year [DOY] 114 to 310) and 1999 (DOY 106 to 316) cotton seasons in Arizona, in which treatments of optimal and low levels of N and water were imposed. In the 1998 season, water treatments were not imposed until late in the season (DOY 261), well after full cover. Following an early season N application in 1998 for the optimal (DOY 154) but not the low N treatment, the CCCI detected significant differences in crop N status between the N treatments starting on DOY 173, when canopy cover was about 30%. A common vegetation index, the ratio of NIR to red (RVI), also detected significant separation between N treatments, but RVI detection occurred 16 days after the CCCI response. After an equal amount of N was applied to both optimal and low N treatments on DOY 190 in 1998, the CCCI indicated comparable N status for the N treatments on DOY 198, a trend not detected by RVI. In the 1999 season, both N and water treatments were imposed early and frequently during the season. The N status was poorly described by both the CCCI and RVI under partial canopy conditions when water status differed among treatments. However, once full canopy was obtained in 1999, the CCCI provided reliable N status information regardless of water status. At full cotton cover, the CCCI was significantly correlated with measured parameters of N status, including petiole NO 3 -N (r = 0.74), SPAD chlorophyll (r = 0.65), and total leaf N contents (r = 0.86). For well-watered cotton, the CCCI shows promise as a useful indicator of cotton N status after the canopy reaches about 30% cover. However, further study is needed to develop the CCCI as a robust N detection tool independent of water stress.