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The current cotton (Gossypium hirsutum L.) fallow farming system causes soil degeneration and cotton yield reduction. Cover cropping is commonly associated with improved soil fertility and crop pro...

The cotton-wheat double-cropping system is widely used in the Yellow River Valley of China, but whether and how different planting patterns within cotton-wheat double-cropping systems impact heat and light use efficiency have not been well documented. A field experiment investigated the effects of the cropping system on crop productivity and the capture and use efficiency of heat and light in two fields differing in soil fertility. Three planting patterns, namely cotton intercropped with wheat (CIW), cotton directly seeded after wheat (CDW), and cotton transplanted after wheat (CTW), as well as one cotton monoculture (CM) system were used. Cotton-wheat double cropping significantly increased crop productivity and land equivalent ratios relative to the CM system in both fields. As a result of increased growing degree days (GDD), intercepted photosynthetically active radiation (IPAR), and photothermal product (PTP), the capture of light and heat in the double-cropping systems was compared with that in the CM system in both fields. With improved resource capture, the double-cropping systems exhibited a higher light and heat use efficiency according to thermal product efficiency, solar energy use efficiency (Eu), radiation use efficiency (RUE), and PTP use efficiency (PTPU). The cotton lint yield and biomass were not significantly correlated with RUE across cropping patterns, indicating that RUE does not limit cotton production. Among the double-cropping treatments, CDW had the lowest GDD, IPAR, and PTP values but the highest heat and light resource use efficiency and highest overall resource use efficiency. This good performance was even more obvious in the high-fertility field. Therefore, we encourage the expanded use of CDW in the Yellow River Valley, especially in fields with high fertility, given the high productivity and resource use efficiency of this system. Moreover, the use of agronomic practices involving a reasonably close planting density, optimized irrigation and nutrient supply, and the application of new short-season varieties of cotton or wheat can potentially enhance CDW crop yields and productivity.

A field experiment was performed to assess the carbon footprint (CF) of four cropping systems to identify the sustainable cropping system. The four cropping systems were cotton monoculture (CM), wi...

The photosynthetically active radiation (PAR) of crop canopy is highly related to yield formation, but how it relates to yield and yield distribution is not well understood. The focus of this study was to explore the relationship between light competition under different densities and yield distributions of cotton. The experiment was conducted in 2019 and 2020 at the Cotton Research Institute of the Chinese Academy of Agricultural Sciences in Anyang city, Henan Province, China. A randomized block design was employed, with a total of three repeats. Each repeat had six density treatments: D1: 15,000, D2: 33,000, D3: 51,000, D4: 69,000, D5: 87,000, and D6: 105,000 plants·ha−1. As predicted, the results showed that the canopy light interception, leaf area index, plant height, and biomass of high-density cotton were higher than those of low-density cotton. The aboveground biomass produced by D6 was the highest, and was 12.9, 19.5, 25.4, 46.3, and 69.2% higher in 2019 and 14.3, 19.9, 32.5, 53.7, and 109.9% higher in 2020 than D5, D4, D3, D2, and D1, respectively. Leaf area, plant height, biomass, boll number, and boll weight were significantly correlated with the light interception rate. D5 (87,000 plants·ha−1) had a higher light interception rate and the highest yield. The highest lint yields produced by D5 were 1673.5 and 1375.4 kg·ha−1 in two years, and was 3.2, 4.3, 5.6, 9.7, and 24.7% higher in 2019, and 6.8, 10.6, 13.5, 21.5, and 34.4% higher in 2020 than D6, D4, D3, D2, and D1, respectively. The boll retention of the lower fruit branch under D5 reached 0.51 and 0.57 in two years, respectively. The shedding rate of the upper fruit branch decreased with the increase in cotton density in two years. The boll retention rate and shedding rate in the lower part of cotton plants were most closely related to light interception, with R2 values of 0.91 and 0.96, respectively. Our study shows cotton yield could be improved through higher light interception by optimizing planting density and canopy structure.

Cotton-winter fallow is the major cropping system of cotton in the Yellow River basin of China, which not only leads to a considerable waste of land and natural resources, but also high greenhouse emissions and a loss of reactive nitrogen. Replacing winter bare fallow in cotton production with February orchid as a cover crop is a new cropping system in this area, but its sustainability is still unknown. Therefore, a field experiment was conducted with two cropping systems (cotton-winter fallow and cotton-February orchid) under four nitrogen application rates (0, 112.5, 168.75, and 225 kg N ha−1). Field observations were incorporated into a life cycle assessment to estimate the carbon footprint, nitrogen footprint, net ecosystem economic benefits, and economic benefits. The estimated carbon footprint per unit of sown area was 43.6–76.1% lower in the cotton-February orchid system than in the cotton-winter fallow system, mainly because of the increase in soil organic carbon. The cotton-February orchid system significantly increased the nitrogen footprint per unit of sown area by 6.7–11.5% under different application rates mainly because of the increase in N2O emissions. The nitrogen application rate significantly impacted the carbon and nitrogen footprints. After accounting for changes in the nitrogen and carbon footprints, the cotton-February orchid system with 168.75 kg N ha−1, which resulted in the highest net ecosystem economic benefits and economic benefits, resulted in a 25.0% reduction in nitrogen fertilizer applied and a 9.5% increase in net ecosystem economic benefits compared with the conventional cotton-winter fallow system and nitrogen fertilizer application rate (225.75 kg N ha−1). Thus, adopting an integrated strategy combining February orchid as a cover crop and a reduced nitrogen fertilizer application contributes to improvements in green and sustainable cotton production systems in the Yellow River basin and other regions with similar ecological conditions.

Modification of the cotton canopy results in shade avoidance and competition for light, which shows that density and spatial arrangement of cotton have a great impact on light interception. This experiment was conducted in 2018 and 2019 in the experimental field at the Institute of Cotton Research of Chinese Academy of Agricultural Science in Anyang city, Henan Province, China. Six plant densities of cotton variety SCRC28 were used to assess spatial competition for light in cotton populations during the whole growing period. Light interception data were collected and analyzed according to the spatial grid method and the extension of Simpson&rsquo, s 3/8 rule. The results showed that at the bottom of the canopy, greater light interception was observed at high densities than at low densities, while in the external part of the layer of the canopy in the horizontal direction, low light interception was recorded at low densities. Leaf area, aboveground biomass and plant height were obviously correlated with light interception, and the cotton population with a higher density (8.7 plants m&minus, 2) performed best at the light interception competition, and with the highest yield. The results will provide guidance on light management through the optimization of the structure of the canopy to provide more solar radiation and a significant basis by which to improve the management of light and canopy architecture.

Cotton (Gossypium hirsutum L.) yield variability over time is determined by weather and agronomic factors in site-specific soil conditions. Plant density is among the most important agronomic practices in cotton production. However, the relative importance of each factor remains unclear. Here, we addressed plant density effects and the relative importance against weather factors on yield variability over time using a decade-long (2008–2017) field experiment on cotton crops that consisted of a wide range of plant densities from 1.5 to 10.5 plants m–2 in the Yellow River Valley of China. The results showed that a plant density of 3.3 plants m–2 produced stable productivity across periods of contrasting weather conditions. However, the average plant density for maximum yield was 5.9 plants m–2. As such, there was a trade-off between yield potential and yield stability for cotton crops. Moreover, plant density and weather explained 46.4 % and 29.1 %, respectively, of the variation in cotton yield during 2008–2017. Among weather related factors, air temperature during the growing season had stronger independent explanatory power (25.8 %) than did sunshine hours (5.1 %) and annual precipitation (1.3 %). Taken together, our results not only highlight the importance of focusing on yield stability for sustainable agricultural management recommendations but also underline the necessity of considering the primary weather variations for accurately predicting agricultural yield under climate change.

Different cotton (Gossypium hirsutum L.)-wheat (Triticum aestivum) planting patterns are widely applied in the Yellow River Valley of China, and crop yield mainly depends on light interception. However, little information is available on how cotton canopy light capturing and yield distribution are affected by planting patterns. Hence, field experiments were conducted in 2016 and 2017 to study the response of cotton canopy light interception, square and boll distribution, the leaf area index (LAI) and biomass accumulation to three planting patterns: a cotton monoculture (CM, planted on 15 May) system, a cotton/wheat relay intercropping (CWI, planted on 15 May) system, in which three rows of wheat rows were intercropped with one row of cotton, and a system in which cotton was directly seeded after wheat (CWD, planted on 15 June). The following results were obtained: 1) greater light capture capacity was observed for cotton plants in the CM and CWI compared with the CWD, and the light interception of the CM was 22.4% and 51.4% greater than that of the CWI and CWD, respectively, at 30 days after sowing (DAS) in 2016; 2) more bolls occurred at the first sympodial position (SP) than at other SPs for plants in the CM; 3) based on the LAI and biomass accumulation, the cotton growth rate was the greatest in CWD, followed by CM and CWI; and 4) the CM produced significantly greater yields than did the other two treatments because it yielded more bolls and greater boll weight. Information on the characteristics of cotton growth and development in response to different planting patterns would be helpful for understanding the response of cotton yields to planting patterns and would facilitate the improvement of cotton productivity.

Background Within-canopy interception of photosynthetically active radiation (PAR) impacts yield and other agronomic traits in cotton (Gossypium hirsutum L.). Field experiments were conducted to investigate the influence of 6 cotton varieties (they belong to 3 different plant types) on yield, yield distribution, light interception (LI), LI distribution and the relationship between yield formation and LI in Anyang, Henan, in 2014 and 2015. Result The results showed that cotton cultivars with long branches (loose-type) intercepted more LI than did cultivars with short branches (compact-type), due to increased LI in the middle and upper canopy. Although loose-type varieties had greater LI, they did not yield significantly higher than compact-type varieties, due to decreased harvest index. Therefore, improving the harvest index by adjusting the source-to-sink relationship may further increase cotton yield for loose-type cotton. In addition, there was a positive relationship between reproductive organ biomass accumulation and canopy-accumulated LI, indicating that enhancing LI is important for yield improvement for each cultivar. Furthermore, yield distribution within the canopy was significantly linearly related to vertical LI distribution. Conclusion Therefore, optimizing canopy structure of different plant type and subsequently optimizing LI distribution within the cotton canopy can effectively enhance the yield.

Increasing plant density has been an effective way for cotton yield improvements. The density of plants in a community also determines competition intensity and the efficiency to exploit available resources. However, the competition response as well as optimal density for yields and the mechanisms of which in terms of fruit growth rate are poorly known. A field experiment was conducted on cotton (Gossypium hirsutum L. SCRC 28) at a wide range of plant densities from 1.5–10.5 plants m−2. The results indicated that intraspecific competition between cotton plants increased nonlinearly with increasing plant density. Seedcotton yield per unit ground area declined precipitously at plant densities below the 4.0 plants m−2 threshold and yield did not further increase above this threshold, which is interpreted as the minimum plant density at which yield should be maximized. Moreover, maximum fruit production and fruit growth rate were also recorded at the same density threshold, above which there was no significant response. Cotton yield was positively correlated with fruit production and fruit growth rate. We thus conclude that high fruit production and fruit growth rate are responsible for maximum yield under optimal plant density in cotton.

15%, 28&ndash, 30%, 21&ndash, 1) and lint yield (1682 kg ha&minus, D2, 33,000, 55%, 40&ndash, D3, 51,000, 15%, 12&ndash, 20%, 7&ndash, 26%, 11&ndash, 37%, 22&ndash, 13% and 13&ndash, 1) was produced by D5. The seed cotton and lint yield produced by D5 were 51&ndash, 1) and maximum (126 VM kg ha&minus, D5, 87,000 and D6, 105,000 ha&minus, 8 the rate decreased slowly and then increased dramatically. The highest seed cotton yield (4546 kg ha&minus, 17% higher than D1, D2, D3, D4 and D6 during both years of experimentation, respectively. The increase in seed yield was due to higher biomass accumulation in reproductive organs under D5 plant density. The highest average (110.4 VA kg ha&minus, 1) rate of reproductive organs biomass was also accumulated by D5 as compared to other plant densities. The results suggest that D5 is the optimal plant density for high reproductive biomass accumulation and high yield for the area of Henan province., 1 d&minus, 24%, 15&ndash, D4, 69,000, 1). Cotton grown at lower plant density produced taller plants and high number of leaves per plant while greater number of branches, fruiting nodes and high number of bolls per unit of ground area were produced under high plant density. Boll retention rate decreased as plant population increased and at nodes 1&ndash, The number of cotton plants grown per unit of ground area has gained attention due to the high prices of inputs and lower production. Cotton yield per unit of area in Henan province has been stagnant in the last few years. The objectives of this study were to investigate cotton growth, yield, boll spatial distribution and biomass accumulation using different plant densities at cultivation and to find out the optimal plant density. A 2-year field experiment was conducted in a randomized complete block design under six plant densities (D1, 15,000

Identifying the characteristics of light interception and utilization is of great significance for improving the potential photosynthetic activity of plants. The present research investigates the differences in absorbing and converting photosynthetically active radiation (PAR) among various cotton cultivars. Field experiments were conducted in 2012, 2013 and 2014 in Anyang, Henan, China. Ten cultivars with different maturity and plant architectures were planted at a density of 60,000 plants ha-1 in randomized blocks, with three replicates. The spatial distribution of light in canopy was measured and quantified with a geo-statistical method, according to which the cumulative amount of intercepted radiation was calculated by Simpson 3/8 rules. Finally, light interception was analyzed in association with the biomass accumulation of different cultivars. The key results were: (1) late-maturing varieties with an incompact plant architecture captured more solar radiation throughout the whole growth period than middle varieties with columnar architecture and even more than early varieties with compact architecture, and they produced more biomass; (2) the highest PAR interception ratio and the maximum biomass accumulation rate occurred during the blossoming and boll-forming stage, when leaf area index (LAI) reached its peak; (3) the distribution within the canopy presented a significant spatial heterogeneity, and at late growing stage, the PAR was mainly intercepted by upper canopies in incompact-type plant communities, but was more homogeneous in columnar-type plants; however, the majority of radiation was transmitted through the canopy in compact-type colonies; (4) there was not a consistent variation relationship between the cumulative intercepted PAR (iPAR) and biomass among these cultivars over the three years of the study. Based on these results, we attempted to clarify the distinction in light spatial distribution within different canopies and the patterns of PAR interception in diverse cotton cultivars with different hereditary characters, thereby providing a significant basis for researchers to select cultivars with appropriate growth period and optimal plant architecture for improvement of light interception and utilization.

In this study, transplanting cotton seedlings grown in artificial substrate is considered due to recent increased interest in cotton planting labor saving approaches. The nursery methods used for growing cotton seedlings affect root growth. However, the underlying functional responses of root growth to variations in cotton seedling transplanting methods are poorly understood. We assessed the responses of cotton (Gossypium hirsutum L.) roots to different planting methods by conducting cotton field experiments in 2012 and 2013. A one-factor random block design was used with three replications and three different cotton planting patterns (substrate seedling transplanted cotton (SSTC), soil-cube seedling transplanted cotton (ScSTC) and directly sown cotton (DSC). The distributions and variances of the root area density (RAD) and root length density (RLD) at different cotton growing stages and several yield components were determined. Overall, the following results were observed: 1) The RAD and RLD were greatest near the plants (a horizontal distance of 0 cm) but were lower at W20 and W40 cm in the absence of film mulching than at E20 and E40 cm with film mulching. 2) The roots were confined to shallow depths (20-40 cm), and the root depths of SSTC and DSC were greater than the root depths of ScSTC. 3) Strong root growth was observed in the SSTC at the cotton flowering and boll setting stages. In addition, early onset root growth occurred in the ScSTC, and vigorous root growth occurred throughout all cotton growth stages in DSC. 4) The SSTC plants had more lateral roots with higher root biomass (RB) than the ScSTC, which resulted in higher cotton yields. However, the early onset root growth in the ScSTC resulted in greater pre-frost seed cotton (PFSC) yields. These results can be used to infer how cotton roots are distributed in soils and capture nutrients.

The partitioning of light is very difficult to assess, especially in discontinuous or irregular canopies. The aim of the present study was to analyze the spatial distribution of photosynthetically active radiation (PAR) in a heterogeneous cotton canopy based on a geo-statistical sampling method. Field experiments were conducted in 2011 and 2012 in Anyang, Henan, China. Field plots were arranged in a randomized block design with the main plot factor representing the plant density. There were 3 replications and 6 densities used in every replicate. The six plant density treatments were 15,000, 33,000, 51,000, 69,000, 87,000 and 105,000 plants ha(-1). The following results were observed: 1) transmission within the canopy decreased with increasing density and significantly decreased from the top to the bottom of the canopy, but the greatest decreases were observed in the middle layers of the canopy on the vertical axis and closing to the rows along the horizontal axis; 2) the transmitted PAR (TPAR) of 6 different cotton populations decreased slowly and then increased slightly as the leaves matured, the TPAR values were approximately 52.6-84.9% (2011) and 42.7-78.8% (2012) during the early cotton developmental stage, and were 33.9-60.0% (2011) and 34.5-61.8% (2012) during the flowering stage; 3) the Leaf area index (LAI) was highly significant exponentially correlated (R(2) = 0.90 in 2011, R(2) = 0.91 in 2012) with the intercepted PAR (IPAR) within the canopy; 4) and a highly significant linear correlation (R(2) = 0.92 in 2011, R(2) = 0.96 in 2012) was observed between the accumulated IPAR and the biomass. Our findings will aid researchers to improve radiation-use efficiency by optimizing the ideotype for cotton canopy architecture based on light spatial distribution characteristics.