The mineralization of crop residue-nitrogen (N) is important for sustainable N supply to subsequent crops. However, the microbial mechanisms regarding residue-N mineralization over growth seasons are still unclear. We amended 15N-labelled maize and soybean residues to a Mollisol soil and found that, after three growth seasons, soybean plants utilized 43% and 37% of soybean and maize residue-N, respectively. Approximately 10.5% of soybean and 18.6% of maize residue-N were recovered in the labile N pools in soil. Over time, 82% of soybean residue-N was mineralized compared with 66% for maize residue-N. Greater increases in abundances of microbial functional genes involved in organic C decomposition, N mineralization, N2 fixation, and denitrification were observed in the soybean residue compared to the maize residue treatment. The study implies that soybean residue amendment may lower fertilizer N input more effectively than maize residue, considering the N balance between crop demand and soil supply in farming Mollisols.

Biochars are recognized for their ability to sequester carbon, improve soil Ph, and reduce aluminum toxicity in acidic soils. This study investigated the changes in a hardwood (sugar maple, Acer saccharum ) biochar after long‐term aging in the soil, and its impact on the growth of soybean and on soil pH and available aluminum concentrations. An agricultural soil was treated with five different levels of biochar equivalent to 0, 40, 80, 120, and 160 Mg ha −1 , in separated plots, using a randomized complete block design (RCBD) with five replications across three growing seasons. The ash content and pH of the aged biochar were significantly reduced (72% and 1.2 units, respectively). The decline in soil pH increased soil‐available aluminum concentration. Additionally, the surface area and pore volume of aged biochar decreased by 69% and 61%, respectively, while the pore size in the aged biochar increased by 27%. Elemental analysis showed that as biochar aged, it was oxidized, decreasing its H:C ratio and increasing its O:C ratio. Furthermore, increased oxidation caused its surface charge to become more negative, with the zeta potential decreasing from −24 to −39.4 mV. Despite substantial changes to the biochar properties with aging, there was no significant effect on soybean yield. The goal of this project is to understand how biochar changes over time in the soil, its effects on soil health and aluminum toxicity, and whether it continues to benefit crops like soybeans, helping farmers and researchers make sustainable decisions about its long‐term use.

Deployment of utility-scale solar power plants could lead to agricultural land-use changes. Agrivoltaics, a dual land use combining solar and agriculture on the same land, can provide multiple environmental benefits, including improving soil quality and water use efficiency. The body of agrivoltaic field data is still growing, and crop responses to different solar configurations under different local climates are highly varied. We investigate the impact of adding spacing between adjacent solar panels in a fixed-tilt system to improve light diffusion to crops. For four crops (broccoli, peppers, kale, Swiss chard) grown across 3 years in an agrivoltaic system in Massachusetts, we found that only kale had a linearly increasing trend as the inter-panel spacing increased from 0.6 m to 1.5 m (2 ft to 5 ft). However, there were significant year-to-year differences in the yield of agrivoltaic versus control fields. Agrivoltaic and full sun fields produced equivalent yields in a hot, dry year, whereas the full-sun control beds produced more salable yield for all four crops in a warm, wet year. This demonstrates variability of agricultural outcomes and the need for more multi-year studies to ensure agrivoltaic impacts are not under- or overestimated.

This study aimed to identify what affects mineral nitrogen (N) levels in lettuce by testing how different chemicals extract nitrate and ammonium, using continuous flow analysis for measurement. The study's rationale is to explore how agricultural methods and environmental factors impact the nutrition and safety of leafy greens. In this research, we utilized a collection of lettuce leaf samples obtained from our earlier investigation. The study involved examining different cultivars cultivated in diverse fields or greenhouse settings, using organic or conventional fertilizers, to observe the outcomes. To measure the amount of ammonium in leaf tissue, we assessed extraction solutions of 0.001, 0.01, 0.1, 1.0, and 2.0 M potassium chloride (KCl), along with distilled water. These evaluations were conducted using leaves from 16 different lettuce plants cultivated under various production conditions. To quantify nitrate, extracting solutions of 0.01 M calcium chloride (CaCl2), 2% acetic acid, and distilled water with two contact times (15 and 45 min) were evaluated. Increasing contact time increased the recovery of nitrate. Distilled water and calcium chloride were significantly more effective in extracting nitrate than acetic acid. No significant difference occurred between water and the salt solution to extract nitrate from leaf tissue. Moreover, the result revealed that 0.01 M KCl extractant satisfies the recovery of ammonium from the leaves regardless of cultivar, fertilizer source, or amount of N application.

Harvest management practices significantly impact high-quality switchgrass (Panicum virgatum L.) production for combustion. A three-year study at the University of Massachusetts and a Conservation Research Program (CRP) explored the interactive effects of season of harvest (summer, fall, and spring) and cutting height (7.5 vs. 15 cm) on biomass yield, mineral content, and non-structural carbohydrate (NSC) reserves of young (2-yr old) and mature (10-yr old) switchgrass (cv. Cave-in-Rock) stands. Results indicated that delaying harvest from summer to spring led to a 25% decrease in biomass yield in young stands, while mature stands exhibited consistent biomass regardless of the season of harvest. Lowering the cutting height from 15 cm to 7.5 cm increased biomass yield by 19% in the young stands and 22% in the mature stands, offering a promising strategy for optimizing yield. Ash and mineral nutrient concentrations decreased over the study years, with variations observed among harvest seasons. Among NSCs, water-soluble sucrose (WSuc) and total sugars (WTS) increased with each passing year in both young and mature stands. Harvesting in fall resulted in the highest NSC concentration indicating maximum vigor for regrowth over years. Cutting height alone did not have a significant influence on ash and mineral content. The study suggests that reducing cutting height to 7.5 cm maximizes profit without compromising quality or stand vigor. Therefore, we recommend combining a cutting height of 7.5 cm with a fall harvest to maximize switchgrass production, with high quality and NSCs concentrations for increasing farm profit and maintaining switchgrass vigor over time.

Quantifying the straw-nitrogen (N) in soil N pools and exploring soil microbial phylogenetic diversity involved in N mineralization are important for effectively managing crop straw to optimize crop N use under climate change. This study used 15N-labeled rice straw to quantify straw-N mineralization in the rhizosphere and N uptake of rice plants in response to elevated CO2 (700 ppm) and warming (2 °C above ambient). The CO2 and temperature co-elevation resulted in 20 mg kg−1 of straw-N mineralized in the rhizosphere, 50 % greater than the ambient control. A similar trend was found for soil-N mineralization. The CO2 and temperature co-elevation significantly increased the gaseous loss of straw-derived N from the rhizosphere, and straw-N in microbial biomass fraction, soluble organic and mineral N fractions in bulk soil. It also increased microbial biomass N originated from the rhizosphere soil. Irrespective of climatic treatments, the amount of mineralized N from straw and soil was greater in the rhizosphere than bulk soil. The CO2 and temperature co-elevation increased plant N uptake by 32 % with the dominant origin of soil-N rather than straw-N. With straw amendment, elevated CO2 plus warming significantly (p < 0.05) increased the abundance of leucine aminopeptidase (pepA) gene. The abundances of pepA, urease (ureC) and chitinase (chiA) genes were lower in the rhizosphere than in the bulk soil. Elevated CO2 plus warming significantly (p < 0.05) altered urease (ureC) and leucine aminopeptidase (pepA)-relevant community compositions in both rhizosphere and bulk soils, which were in turn associated with the N mineralization. The results suggest that the climate-change-induced shift of the composition rather than gene abundances of microbial communities that are involved in ammonification contributes to faster mineralization of soil N and straw N in paddy soils.

In agricultural systems, residue amendment is an important practice for nutrient management, but the role of microbes in mineralization of crop residue nitrogen (N) is not well known. Therefore, this study aimed to examine how the residue N mineralization was associated with changes of the microbial community composition in crop rhizosphere. A rhizobox system was deployed to separate the rhizosphere zone into the root-growth (central), and 2 mm (proximal) and 4 mm (transitional) zones away from the central zone, and the gradient change of the residue-N mineralization along the zones was assessed. Soybean plants were grown in a Mollisol without or with amendment of 15N-labelled soybean and maize residues. Furthermore, amplicon sequencing was performed to detect the shift of microbial community composition associated with the residue-N mineralization. The residue-N was mineralized faster in the rhizosphere than the bulk soil, and from soybean residue than maize residue. Greater enrichment of taxa against the unit of residue-N mineralization in the soybean than maize residue treatment was correspondent with the enriched ammonification genes, likely contributing to the enhanced mineralization of soybean residue-N in the rhizosphere. A gradual increase in dissolved organic C and a decrease in available N concentration from the central root zone to the bulk soil, might shift bacterial community favoring the residue-N mineralization in the rhizosphere. The spatial changes in chemical properties across the rhizosphere lead to the recruitment of microbiome taxa to enhance the mineralization of N derived from crop residues.

We provide here an overview of the remarkable life and outstanding research of David (Dave) Charles Fork (March 4, 1929–December 13, 2021) in oxygenic photosynthesis. In the words of the late Jack Edgar Myers, he was a top ‘photosynthetiker’. His research dealt with novel findings on light absorption, excitation energy distribution, and redistribution among the two photosystems, electron transfer, and their relation to dynamic membrane change as affected by environmental changes, especially temperature. David was an attentive listener and a creative designer of experiments and instruments, and he was also great fun to work with. He is remembered here by his family, coworkers, and friends from around the world including Australia, France, Germany, Japan, Sweden, Israel, and USA.

The beneficial effect of crop residue amendment on soil organic carbon (SOC) stock and stability depends on the functional response of soil microbial communities. Here we synchronized microbial metagenomic analysis, nuclear magnetic resonance and plant-15N labeling technologies to gain understanding of how microbial metabolic processes affect SOC accumulation in responses to differences in N supply from residues. Residue amendment brought increases in the assemblage of genes involved in C-degradation profiles from labile to recalcitrant C compounds as well as N mineralization. The N mineralization genes were correlated with the C and N accumulation in the particulate and mineral-associated C pools, and plant-derived aliphatic forms of SOC. Thus, the combined C and N metabolic potential of the microbial community transforms residue into persistent organic compounds, thereby increasing C and N sequestration in stable SOC pools. This study emphasizes potential microbially mediated mechanisms by which residue N affects C sequestration in soils.

Investigating the interactive effect of elevated CO2 and warming on photosynthetic carbon (C) detained in soil organic C (SOC) fractions is pivotal to predict the SOC stability in farming soils in response to climate change, especially in a major maize-grown Mollisol, one of most fertile farming soil in the world. Using open top growth chamber (OTC) to mimic the rises of atmospheric CO2 concentration up to 550 ppm and temperature 2 ? above surroundings, one set of maize plants were labelled with (CO2)-C-13 across the first growth season, and the other set of plants were grown in OTCs for four seasons. We found that elevated CO2 increased plant-C in the fine particulate organic C fraction from 0.53 mg kg(-1) under the control to 0.89 mg kg(-1), while warming plus elevated CO2 did not alter plant-C allocation into this fraction. Elevated CO2 increased plant-C accumulated in the mineral-associated C (MOC) fraction, but not C content in this fraction. There was no change of C content in the MOC fraction with plant grown under climatic conditions over time. Climate change may not alter SOC stock but accelerate the fresh-old-C exchange in maize-grown Mollisols as warming may accelerate turnover of plant-derived C.

Crop residue amendment to soil is recommended as an effective management practice to return nutrients, especially in the maize-soybean rotation system where large amounts of maize residues are produced. Quantifying the utilisation of maize-residue N by the subsequent soybean crop is essential for optimising the N fertilisation strategy for sustainable production. However, whether and how maize residue amendment alters N acquisition in soybean plants are largely unknown. It was hypothesised that maize residue would supply N and enhance N2 fixation to meet the N requirements of subsequent soybeans. Three treatments, namely: 1) chemical fertiliser (55.2, 35.2 and 22.4 kg ha- 1 of N, P and K, respectively), 2) maize residue (8 t ha- 1), and 3) nonfertiliser were applied in a maize-soybean rotation system in a Mollisol soil. It was demonstrated that soybean seed yield in the maize-residue treatment was the same as that in the chemical fertiliser treatment, with 2.9 vs. 3.2 t ha- 1 in 2014, 2.7 vs. 2.6 t ha- 1 in 2016, and 3.0 vs. 3.1 t ha- 1 in 2018. A follow-up pot experiment using 15N-labelled residue indicated that the residue-derived N accounted for 0.5 % of the total N in soybean seeds and the proportion of symbiotically fixed N reached 82 %. The amount of fixed N during the pod-filling period in the residue treatment was 0.66 g plant-1, which was 49 % and 41 % higher than those in the chemical fertiliser and non-fertiliser treatments, respectively. The stimulation of N2 fixation was associated with an increase in fixed N per nodule and the enrichment of diazotrophs in the rhizosphere of soybean. With maize residue amendment, the increased N2-fixing capability of nodules during the reproductive period, rather than residue-derived N, fulfilled the N demand for maintaining seed yield of soybean. In the maize-soybean rotation system, maize residue amendment would facilitate the N2 fixation to partly substitute for N fertiliser for soybean production in Mollisols.

大气CO2浓度和温度升高会通过影响作物的光合作用,从而影响光合碳向土壤中的输送.输入到土壤中光合碳含量的变化势必会对土壤外源碳的主要分解者--微生物的群落结构产生影响.土壤微生物在土壤有机质的转化过程中发挥着重要的作用,是土壤碳循环的主要驱动者,其群落结构和功能的改变会影响土壤有机质的动态变化,而这些变化会进一步增加或者降低大气中的CO2浓度,从而对气候变化产生反馈作用.未来土壤的碳平衡取决于大气CO2浓度和全球变暖对土壤中碳的输入、输出以及碳在土壤中的驻留时间.因此,只有全面了解大气CO2浓度和温度升高将对土壤碳库及土壤微生物群落结构产生何种影响,才能明确地揭示陆地生态系统对气候变化的反馈机制,对未来农田土壤有机碳库的管理和生产力的维持有重要意义.文章综述了大气CO2浓度和温度升高及其交互作用对土壤碳库和土壤微生物群落结构的影响.主要结论为:(1)大气CO2浓度和温度升高对土壤碳库的影响可以相互抵消,但是土壤碳库是否成为碳"源"与温度升高的幅度密切相关;(2)大气CO2浓度升高增加了光合碳在玉米、小麦等植株各部分的分配,温度升高同样对光合碳的分配规律产生影响,但对不同部位的影响不一致,多呈降低或无显著影响;(3)大气CO2浓度和温度升高可能对土壤微生物活性及其群落结构产生交互影响,且对不同微生物(细菌、真菌和古菌)群落的影响程度不同,进一步对土壤有机碳的转化产生影响.最后提出未来的研究方向:(1)从气候变化影响植物-土壤互作角度解析根系分泌物的转化过程及其对微生物的影响;(2)通过DNA-SIP进一步研究大气CO2浓度和温度升高条件下土壤微生物对不同植物来源碳的选择性利用与碳循环的关系,从而阐明气候变化条件下微生物底物利用策略以及微生物群落结构的变化.

Establishment of switchgrass (Panicum virgatum L.) is challenging, and failure in establishment may expose growers to considerable economic risk. The objectives of this research were to (i) evaluate whether management practices are variety-specific for the establishment of switchgrass and (ii) assess the effectiveness of cover crops as preceding crops on ‘Shawnee’ switchgrass establishment. Therefore, two studies were conducted at the University of Massachusetts Agricultural Experiment Station in Deerfield, MA, USA, in the 2011–2012 and 2012–2013 growing seasons. In Experiment 1, cover crop treatments (fallow, oat (Avena sativa L.) and rye (Secale cereale L.)) were the main plots, the two seeding methods (no-till drill and a cultipacker seeder (Brillion)) were the sub-plots, and the two varieties (‘Cave-in-Rock’ (CIR) and Shawnee)) were the sub-sub-plots. The second study was conducted using Shawnee switchgrass and involved the three cover crop treatments used in Experiment 1 using a cultipacker seeder with seed firming prior to planting but not afterwards (consistent in both experiments). The results indicated that a combination of oat and no-till resulted in higher tiller density (493%), lower weed biomass (77%), increased switchgrass biomass (SGB) (283%) and SGB to weed biomass (WB) ratio. Compared with Shawnee, CIR planted into a winter-killed oat residue had higher tiller density (93%), lower weed biomass (18%), higher switchgrass yield (128%) and thus a greater SGB:WB ratio (507%). Trends of switchgrass response to management practices, however, were similar between the two varieties, indicating that seed quality rather than management practices could influence switchgrass’s response to management practices. In Experiment 2, Shawnee tiller density was suppressed by rye as the preceding crop, possibly due to late termination of rye. Shawnee switchgrass yields were below 1000 kg ha−1 under all management practices; thus, harvesting should happen in the year following establishment. Future research should focus on comparing no-till drilling with cultipacker seeder with rolling not only before but after seeding to increase seed–soil contact.

Climate change may fundamentally affect the microorganisms in the rhizosphere that drive soil C and nutrient cycles. This study aimed to clarify the response of rhizobacterial community to warming and elevated CO2 (eCO(2)) in typical maize (Zea mays L.)-growing soils. Under climate change, the shift of rhizobacterial community composition was assumed to be different among soils, which would be associated with the C sequestration and stability in soils. Using open-top chambers to mimic climate warming and eCO(2), we examined the taxonomic composition of bacterial communities in the rhizosphere of maize grown in four farming soils (Acrisol, Fluvisol, Kastanozem, and Phaeozem). Warming decreased the richness of the rhizobacterial community by 3.8% across the soils, but eCO(2) did not significantly alter community richness. The shift in bacterial community composition was greater under warming than under eCO(2), and the shift was different among soils. The abundance of Streptomyces and Gaiella significantly increased in Phaeozem and Acrisol in response to warming but not in Fluvisol or Kastanozem. Sphingomonas was suppressed in Phaeozem under warming, whereas Sphingomonas, Shinella, and Rhodospirillaceae_norank were enriched in the other three soils. Soil chemical characteristics including nitrate, Olsen P, available K, and soil organic C (SOC) were significantly associated with a number of dominant operational taxonomic units. These results indicate that the effect of warming on bacterial community composition in the rhizosphere of maize may be stronger than the effect of eCO(2). Climate change led to various changes in the rhizobacterial community composition among soils that might be associated with the quality of SOC and nutrient status in different soils.

Crop residue amendment is likely to stimulate symbiotic N2 fixation, and clarifying its effect on N2-fixing bacteria, i.e., diazotrophs in the rhizosphere of legume crops, is important for sustainable N management in legume-cereal cropping systems. Therefore, this study aimed to reveal the diazotrophic community composition in the rhizosphere of soybean in response to maize residue amendment. Being designed with treatments of maize residue, chemical fertilizer, and non-fertilizer applications, this study deployed the 15N-labeling technology combined with high-throughput sequencing of the nifH gene as a molecular marker for diazotrophs to quantify the symbiotically-fixed N2 in soybean plants and link symbiotically fixed N2 to the diazotrophic community diversity in the rhizosphere. Residue amendment increased the abundance of diazotrophs and fundamentally altered the composition of its community in the rhizosphere. It increased the relative abundances of Bradyrhizobium and Azohydromonas compared to the chemical fertilizer treatment. The copy number of nifH in the rhizosphere was associated with dissolved organic carbon and N2 fixation. Residue-induced increase in dissolved organic carbon may provide sufficient carbon sources for diazotroph enrichment and thus enhance nodulation. The maize residue amendment may enrich N2 fixers to facilitate nodulation and subsequent N2 fixation of soybean, highlighting the eco-functional importance of diazotrophs fixing extra N into the rotation system.

Warming and elevated CO2 (eCO(2)) may influence the input of photosynthetic carbon (C) into soils and subsequent soil C storage. The biochemical properties vary among soils, which likely act different roles in the fate of photosynthetic C and soil C sequestration in response to warming and eCO(2). However, the interactive effects of climate change and soil types on the photosynthetic C retained in soil and relevant mechanisms are poorly understood. We performed a pot experiment in open-top chambers to examine the effects of eCO(2) (550 ppm) combined with elevated temperature (eT, 2 degrees C higher than the air temperature) on the retention of plant-C of maize (Zea mays L.) grown in Phaeozem, Fluvisol, Kastanozem and Acrisol with (CO2)-C-13 labeling at the silking stage. The proportion of C-13 to the total fixed C-13 increased by 44.6%, 96.1% and 41.9% in Phaeozem under eT, eCO(2) and eT plus eCO(2) treatments compared with control, while decreased in other three soils in response to either eCO(2), eT or eT plus eCO(2). The effect of climate change on fresh C input in maize cropping soils depended on soil type, and soil net C losses may occur in the Fluvisol, Kastanozem and Acrisol under climate change.

Intercropping existed early in the evolution of agriculture. However, for several decades, use of this sustainable cropping system approach remained limited to small operations in developing nations. Intensified monoculture production requires increased inputs to maximize productivity; this has resulted in compromised soil health, water and air quality issues due to nitrate, phosphorous, and pesticide runoff and leaching, greenhouse gas emissions, and thus reduced sustainability of farming systems. Well-designed intercropping operations efficiently use natural resources, increase biodiversity, manage pests, and in many instances, enhance crop productivity and quality, and natural soil fertility with reduced consumption of off-farm inputs. The primary consideration in intercropping is selecting compatible crops to minimize competitive inhibition, allow for ease of field management, and increase profit per land unit compared to monocultures. This chapter aims to review more than 50 years of literature addressing intercropping. Following a discussion of tradeoffs and considerations of common types of intercropping, various methods of economic assessments as well as ecosystem services and environmental benefits of intercropping will be reviewed.

Dairy farmers in the northeast face challenges in the application of manure in fall and on-time planting of cool-season grasses to maximize recovery of residual N and nutrients released from fall applied manure. Ammonia emission from animal manure is a serious environmental concern and can be reduced if cover crop is integrated in the farming system. On-time planting of cover crops can reduce ammonia volatilization from fall, surface-applied manure, and prevents N loss to leaching. A two-year study was conducted in 2015 and 2016 to investigate if time of planting of winter annual rye (Secale cereale L.) along with late fall application of manure when air temperature is low can influence ammonia emission and preserve nitrogen (N) to meet the N requirement of forage rape. Three planting dates (16 September, 30 September, and 14 October) of rye cover crop with two manure application treatments including late-fall application and no manure were assessed for mitigating ammonia volatilization, and also yield and recovery of N by forage rape (Brassica napus L.). The highest rates of ammonia volatilization were detected in the first 24 hours after manure spreading regardless of the treatment. The result indicated that cover crop use significantly limited volatilization compared with no cover crop. The earliest planting date produced 3823 kg ha−1 dry matter of winter rye cover crop that was 16 and 35 percent higher than second and third dates of planting, respectively. The manured cover crop accumulated 132 kg N ha−1 when planted early. However, biomass yield of forage rape was more when planted after all cover crop treatments with manure application. Prior to forage planting, the nitrate-N content in all three soil depths (0–20, 20–40, and 40–60 cm) in the plots with manure was higher than plots with no manure. No significant differences in forage rape yield was detected among winter rye planting dates; however, forage rape planted after winter rye was higher than after no-cover crop. The results of this study suggest that when immediate incorporation of manure into soil is not feasible, establishing cover crop early and then applying manure in the late fall, is a practical management to limit nonpoint source pollution from ammonia loss.

Field and pot experiments were conducted to select and identify the characteristics of potassium (K) high efficiency vegetable soybean genotypes. Forty genotypes under two potassium application levels (0, 120 kg ha(-1) K2SO4) showed variations in K concentration, K accumulation, K internal use efficiency (KIUE) and K harvest index (KHI) in field experiment conducted in 2016. According to the distinct KIUE for yield (KIUE-Y) and KHI, two K high efficiency (KHE) genotypes (T117, L113) and two K low efficiency (KLE) genotypes (DZ1, ZX8) were used in pot experiment with two K levels (0, 120 kg ha(-1) K2SO4) in 2017 for further investigation. Results indicated that KIUE-Y was significantly correlated with harvest index (HI) and KHI. Both K and dry matter (DW) were optimally distributed in the seed of KHE genotypes. In contrast, more DW and K were accumulated in vegetative organs of KLE genotypes, which was the main reason limiting K efficiency. Under K deficiency, KHE genotypes better regulate their DW and K distribution, and have higher specific leaf weight with unaffected leaf area.

Water is a crucial factor affecting expression of crop yield potential. A field experiment was conducted during 2014 and 2015 to determine the effect of limited water on growth, yield, water productivity (WP), nutritive value, and physiological parameters of silage corn (Zea mays L.) grown in a semi-arid region. Hybrid 'P8107HR' was planted in replicated plots under 100ETc (100% crop evapotranspiration), 80ETc, 60ETc, and limited 100ETc (100ETc from planting to V9, no water from V9 to R3, then 100ETc again) managed with a surface drip irrigation. Canopy height, leaf area index (LAI), specific leaf area (SLA), biomass yield, WP, and nutritive value were determined. Photosynthesis (A), stomatal conductance (gs), transpiration (E), and intrinsic WP (iWP) were obtained with an infrared gas analyzer from V14 to R2 stages. Relative water content (RWC) of leaves was determined at V8, V12, VT, and R3 stages. Results showed that canopy height and biomass yield were greatly affected by water stress. Biomass yield decreased by 40% in the limited 100ETc treatment compared to 100ETc, with no effect of irrigation on nutritive value. Water-stressed plants from V14 to R2 were affected in their ability to perform gas exchange and exhibited changes in crop growth and biomass yield. RWC was affected by water stress, mostly under 60ETc at V8 (71%) and VT (78%). Overall, limited water at late vegetative and early reproductive stages affected physiology and yield of silage corn, indicating that irrigation timing is a key factor for optimizing silage corn production in water-scarce regions.