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Sowing cotton directly after harvesting wheat in the Yangtze River Valley of China requires early mature of cotton without yield reduction. Boll-setting period synchronisation and more yield bolls distributed at the upper and middle canopy layers are also required for harvesting. The objective of this study is to quantify the individual and interaction effects of plant density and plant growth regulator mepiquat chloride (MC) on temporal and spatial distributions of yield bolls, as well as yield and yield components. During the 2013–2016 cotton growing seasons, the experiments were conducted on a short-season cotton cultivar CRRI50 at Yangzhou University, China. Various combinations of plant density (12.0, 13.5 and 15.0 plants m−2) and MC dose (180, 270 and 360 g ha−1) were applied on cotton plants. The combination of 13.5 plants m−2 and 270 g ha−1 MC resulted in the greatest boll number per unit area, the highest daily boll setting number and more than 90% of bolls positioned within 45–80 cm above the ground. In conclusion, appropriate MC dose in combination of high plant density could synchronize boll-setting period and retain more bolls at the upper and middle canopy layers without yield reduction in the system of direct-seeded cotton after wheat harvest, and thus overcome the labor-intensive problem in current transplanting cropping system.

In Ethiopia, particularly Southern Regional State dry land crop productivity is majorly influenced by low soil moisture stress. The current study has been conducted to evaluate the effect of intercropping maize with legumes covers on Soil Moisture improvement at Misrak Azerinet Berbere woreda. Seven treatments evaluated were vetch with maize, lablab with maize, vetch only, lablab only, and maize only. The experimental design was in a randomized complete block design (RCBD) with three replications in a permanent plot. Disturbed soil samples were collected from the intra-row spacing from both intercropped and non-intercropped plots from the depth of 0–20 cm and composited for soil moisture analysis. The yield and biomass of maize and legume shrubs have been collected. The Land Equivalent Ratio (LER) was computed to evaluate the land productivity of intercropped combinations. The result reveals that in both years, yield, biomass, and soil moisture content were not significant (p > 0.05) at a statistically significant level. After crop harvest, maize with lablab has better soil moisture relative to other combinations (first year). In both years, the soil moisture content in the soil was reduced in the sole crop of maize compared with sole vetch. However, the soil moisture content in the soil was increased in maize intercropped with lablab in both development stage and after harvest compared with maize intercropped with vetch. Both legume shrubs under mono and intercropped conditions conserve soil moisture relative to maize under mono cropped conditions. This implies the benefit of legume shrubs on soil moisture conservation both planted under mono cropped conditions and intercropped conditions. It is concluded that the combination of intercropping maize with legume shrubs could substantially increase soil moisture conservation and improve the overall land productivity. Therefore, for maximum maize production, farmers in the area should plant maize with a combination of vetch and lablab. Additionally, farmers should practice double cropping with the residual soil moisture from legume and its combinations.

SummaryThe development of high-yielding, short-duration super-rice hybrids is important for ensuring food security in China where multiple cropping is widely practiced and large-scale farming has gradually emerged. In this study, field experiments were conducted over 3 years to identify the yield formation characteristics in the shorter-duration (∼120 days) super-rice hybrid ‘Guiliangyou 2’ (G2) by comparing it with the longer-duration (∼130 days) super-rice hybrid ‘Y-liangyou 1’ (Y1). The results showed that G2 had a shorter pre-heading growth duration and consequently a shorter total growth duration compared to Y1. Compared to Y1, G2 had lower total biomass production that resulted from lower daily solar radiation, apparent radiation use efficiency (RUE), crop growth rate (CGR), and biomass production during the pre-heading period, but the grain yield was not significantly lower than that of Y1 because it was compensated for by the higher harvest index that resulted from slower leaf senescence (i.e., slower decline in leaf area index during the post-heading period) and higher RUE, CGR, and biomass production during the post-heading period. Our findings suggest that it is feasible to reduce the dependence of yield formation on growth duration to a certain extent in rice by increasing the use efficiency of solar radiation through crop improvement and also highlight the need for a greater fundamental understanding of the physiological processes involved in the higher use efficiency of solar radiation in super-rice hybrids.

Cereal crops especially maize production in Ethiopian Central Rift Valley is affected by biotic and abiotic production. This study was conducted for two seasons (2015-2016) and the best cropping system was identified using Randomized Complete Block Design with three replications. The experiment had six treatments (1) Continuous mono-cropping under conventional practice (CN), (2) continuous mono cropping under conservation agriculture (CA) (3) relay cropping (CA) with double bean planting within a season (maize bean inter-cropping: second round bean planting was conducted after immediate harvesting of the first bean), (4) Double cropping (CA) (maize bean inter cropping after sole lablab), (5) Double cropping (CA) (maize after bean) and (6) Double cropping (CA) (bean after maize). In 2016, the highest maize biomass yield and maximum water use efficiency were obtained from double cropping bean after maize with value of 16050 kg/ha and 31 kg mm-1, respectively. Maize-bean relay cropping outperformed the sole maize under CA and CN by 182 and 138% for maize grain yield. Water use efficiency of double cropping (maize after bean) and relay cropping was higher than double cropping (bean after maize) by 366 and 197% in 2015 for maize grain yield. For biomass, relay cropping under CA and sole maize under CN had similar water use efficiency of 18 kg mm-1. The CA practice with diverse crops planted together: double inter-cropping at different time (relay cropping) and double cropping under CA are good options for using the residual soil moisture and to sustainably improve crop productivity. Key words: Conservation; cropping system; lablab; water use efficiency.

Soil organic matter (SOM) and its fraction play an important role in maintaining and improving soil fertility of paddy field. However, there is still limited information about how SOM fraction response to carbon (C) sequestration with different short-term tillage practices under the double-cropping rice paddy field in southern of China. Therefore, the effects of 5-year short-term tillage treatments on different SOM fractions (physically protected, physico-chemically protected, physico-biochemically protected, chemically protected, biochemically protected, and unprotected) under the double-cropping rice paddy field in southern of China were studied in this paper. The field experiment included four different tillage treatments: rotary tillage with crop residue removed as a control (RTO), conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), and no-tillage with crop residue retention (NT). The results showed that soil unprotected (cPOM), biochemically (NH-dSilt), physically-biochemically (NH-μSilt), and chemically protected (H-dSilt) fractions with different tillage treatments were the mainly C storage fraction in paddy field. The soil organic carbon (SOC) content in unprotected (cPOM and fPOM), physically protected (iPOM), and physico-chemically protected (H-μClay) fractions with CT treatment was increased by 1.45, 2.13, 1.91, and 1.42 times higher than that of RTO treatment, respectively. The results showed that largest proportion of fraction to SOC content was biochemically protected, followed by unprotected and physically-biochemically protected, and physically protected was the lowest. These results indicated that soil physically protected, physically-chemically protected, and physically-biochemically protected fractions with CT and RT treatments were higher than that of NT and RTO treatments. In summary, it was a benefit practice for increasing SOM fraction under the double-cropping rice paddy field in southern of China by combined application of conventional tillage and rotary tillage with crop residue incorporation management.

Land-use change significantly impacts soil micro-nutrients distribution and transformations due to their inefficient scale- and location-specific management in different ecosystems. We studied the changes in micro-nutrients (viz. Zn, Cu, Fe and Mn) availability and their transformations in soils of hilly landscapes under five distinct land-use systems including mono cropping, double cropping, agroforestry, orchards and the vegetable crops to explore relationship between different fractions of variable solubility and their mobility in response to land-use change. Among the compared land-use systems, DTPA-Zn, Fe, Mn and Cu comprised ~ 3.0 to 8.2%, ~ 0.21 to 0.35%, ~ 1.2 to 6.3% and ~ 7.6 to 17.5% of their respective total content in soils. The agroforestry system had significantly (p

Before the introduction of genetically modified insect-tolerant maize (Zea mays L.) in 1997, most of the production of this staple in Argentina was concentrated in humid and sub-humid temperate regions. Early spring sowings minimized the risk of water deficit around flowering and yield reduction due to pests. Use of genetically modified maize allowed optimization of sowing dates to synchronize critical periods for kernel set determination with the times of the year when water deficits are less likely, reducing large interannual variations in grain yield. This change in sowing date did not start until 2009, after the occurrence of two successive dry phases of the El Niño–Southern Oscillation phenomenon. The area of land cropped to maize in Argentina has expanded dramatically since then, particularly beyond the humid areas. Currently, maize is sown in an almost 50%/50% distribution between early and late sowings, including double cropping. Changes in agronomic practices such as sowing date and production area can lead to changes in the timing and intensity of water deficits along the maize growth cycle. This review provides an overview of new patterns of water deficit across humid, sub-humid, and semi-arid mid-latitude environments of Argentina, and their effects on grain yield and yield components.

The soil physicochemical properties and soil microbial community were affected by different fertilizer management. Fertilizer regime was closely related to soil texture and nutrient status in the d...

Improving both grain yield and resource use efficiencies simultaneously is a major challenge in rice production. However, few studies have focused on integrating dense planting with delayed and reduced nitrogen application to enhance grain yield, nitrogen use efficiency (NUE) and radiation use efficiency (RUE) in rice (Oryza sativa L.) in the double rice cropping system in South China. A high-yielding indica hybrid rice cultivar (Yliangyou 143) was grown in field experiments in Guangxi, South China, with three cultivation managements: farmers’ practice (FP), dense planting with equal N input and delayed N application (DPEN) and dense planting with reduced N input and delayed N application (DPRN). The grain yields of DPRN reached 10.6 and 9.78 t ha–1 in the early and late cropping seasons, respectively, which were significantly higher than the corresponding yields of FP by 23.9–29.9%. The grain yields in DPEN and DPRN were comparable. NUE in DPRN reached 65.2–72.9 kg kg–1, which was 61.2–74.1% higher than that in FP and 24.6–30.2% higher than that in DPEN. RUE in DPRN achieved 1.60–1.80 g MJ–1, which was 28.6–37.9% higher than that in FP. The productive tiller percentage in DPRN was 7.9–36.2% higher than that in DPEN. Increases in crop growth rate, leaf area duration, N uptake from panicle initiation to heading and enhancement of the apparent transformation ratio of dry weight from stems and leaf sheaths to panicles all contributed to higher grain yield and higher resource use efficiencies in DPRN. Correlation analysis revealed that the agronomic and physiological traits mentioned above were significantly and positively correlated with grain yield. Comparison trials carried out in Guangdong in 2018 and 2019 also showed that DPRN performed better than DPEN. We conclude that DPRN is a feasible approach for simultaneously increasing grain yield, NUE and RUE in the double rice cropping system in South China.

Soil Olsen P level has a major influence on crop yield, efficient P utilization, and soil fertility. In this study, the optimum Olsen P range was determined from long-term (1990–2012) field experiments in three typical soil types of China under single cropping of maize or double cropping of maize and wheat. The critical soil Olsen P value for crop yield was evaluated using three different models, and the relationships among P use efficiency (PUE), Olsen P, and total P were analyzed. The agronomic critical soil Olsen P values obtained from the three models for the neutral soil of Gongzhuling and the calcareous soil of Zhengzhou were similar; however, the values from the linear-linear and linear-plateau models for both maize and wheat were substantially lower than those from the Mitscherlich model for the acidic soil of Qiyang. The PUE response change rates (linear equation slopes) under different soil Olsen P levels were small, indicating slight or no changes in the PUE as the soil Olsen P increased in all three soils. A comparison of the Olsen P levels that achieved the maximal PUE with the agronomic critical values derived from the three models indicated that the linear-plateau model exhibited the best performance. The regression equation coefficients of Olsen P response to total P decreased as follows: Zhengzhou (73 mg g−1) > Qiyang (65 mg g−1) > Gongzhuling (55 mg g−1). The Olsen P level increased as the total P increased, which may result in a decrease in PUE. To achieve a relatively high crop yield, PUE, and soil fertility, the optimum Olsen P range should be 13–40, 10–40, and 29–40 mg kg−1 at Gongzhuling, Zhengzhou, and Qiyang, respectively.

Made available in DSpace on 2021-06-25T10:45:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The quantification of nutrient uptake and partitioning during crop cultivation, as well as nutrients removed at harvest, are essential information to optimize nutrient management. A 2-yr field experiment was conducted in Botucatu, São Paulo State, southeastern Brazil, to examine the biomass accumulation and nutritional requirements and removal of two safflower (Carthamus tinctorius L.) genotypes cultivated in the fall-winter season of a double-cropping system. Seven plant samplings were performed during the growing season, and the material was divided into stems, leaves, and reproductive structures. Seed yield and nutrient removal were determined at harvest. Safflower genotypes had similar 2-yr average biomass accumulations and seed yields. There were greater plant growth and nutrient uptake from stem elongation to seed filling, compared to the other growth stages. The maximum rates of nutrient uptake were observed near the flowering stage. On average, a maximum uptake of 169 kg N, 16 kg P, 178 kg K, 121 kg Ca, 16 kg Mg, 15 kg S, 130 g Cu, 3298 g Fe, 420 g Mn, and 351 g Zn per hectare were required to produce about 10,500 and 1,400 kg ha−1 of aboveground biomass and seeds, respectively. Relative to the maximum aboveground nutrient accumulation, seeds contained 28% of P, 24% of N, 22% of Zn, 16% of Cu, 11% of Mg, 10% of S, 6% of K, 5% of Mn, 4% of Ca, and 4% of Fe. These quantifications of biomass and nutrient accumulation and partitioning in each growth stage of fall-winter safflower can be used as guidelines for fertilizer recommendations for this crop in double-cropping systems. Dep. of Crop Science College of Agricultural Sciences São Paulo State University (UNESP) Compass Minerals América do Sul Indústria e Comércio SA Center for Tropical Roots and Starches São Paulo State University (UNESP) Bayer Crop Science Dep. of Soil Water and Climate University of Minnesota Dep. of Crop Science College of Agricultural Sciences São Paulo State University (UNESP) Center for Tropical Roots and Starches São Paulo State University (UNESP) FAPESP: 2014/20301-8

“Thin-wet-dry” irrigation (TR) and alternate wetting and drying irrigation (DR) are two effective water-saving irrigation modes used for paddy fields. The objectives of this study were to assess the effects of two water-saving irrigation modes on methane (CH4) and nitrous oxide (N2O) emissions from rice fields in the south of the Tropic of Cancer, south China, and verify the hypothesis about the reducing effect of both TR and DR modes on global warming potential (GWP) and greenhouse gas emission intensity (GHGI) compared with conventional irrigation (CR). Three-year field experiments with three irrigation modes were continuously conducted during 2015–2017 to monitor the changes of CH4 and N2O fluxes during the growing period of double-cropping rice, and then the cumulative CH4 and N2O emissions, GWP, and GHGI were analyzed. Compared with CR mode, both TR and DR saved total irrigation amount by 19.5–40.4 and 27.1–52.5% but did not affect the rice yield; DR lowered CH4 emissions from double-cropping rice field over the whole growing period by 41.1–67.0% and TR only reduced CH4 emissions from 2016 late rice field by 31.4%, but TR and DR increased N2O emissions by 57–271 and 79–825%; DR lowered GWP and GHGI by 40.7–66.8 and 48.3–65.5%, and TR declined GWP and GHGI in 2015 and 2016 late rice fields by 31.3–43.4 and 22.4–49.7%. Moreover, rice season significantly influenced GWP and GHGI. Two water-saving irrigation modes reduced GWP and GHGI and our results can provide scientific basis in precisely estimating greenhouse gas emission in China.

The spatial and temporal variability of soil CO2 emissions from agricultural soils is inherently high. While tillage and crop residue practices play vital roles in governing soil CO2 emission, their effects on the variability of soil CO2 fluxes across depths and seasons are still poorly understood. To address this, an experiment consisting of four treatments, namely conventional tillage with (CT+) and without crop residue application (CT−), as well as no tillage with (NT+) and without crop residue application (NT−), was conducted to investigate soil CO2 fluxes at top 40 cm soils with 10-cm depth intervals in a winter wheat-summer maize rotation system in the North China Plain. Our results showed soil CO2 fluxes increased with depth in both the wheat- and maize-growing seasons. However, the dominant factors in regulating soil CO2 fluxes changed with soil depth and seasons. In the wheat-growing season, increase in soil CO2 fluxes with depth was attributed to the increase of dissolved organic carbon-to-nitrogen ratio (DOC/DON) and a decline in soil DON concentration along the soil profile. These factors explained about 55–96% of the total variation in soil CO2 fluxes at different soil depths. In the maize-growing season, the dominant factors were soil DOC/DON ratio, soil DON concentrations, and soil moisture. These factors explained approximately 79–96% of the total variation in soil CO2 fluxes along the soil depth. Greater soil CO2 fluxes (except at 30–40 cm depth) were observed in NT− than CT− treatments. Furthermore, crop residue application enhanced soil CO2 fluxes across different depths, but the enhancement was more prominent in CT+ than NT+. Moreover, soil CO2 fluxes in the maize-growing season were greater than those in the wheat-growing season. Our results demonstrate that the effects of tillage regimes and crop residue management practices on soil CO2 emissions are not confined only to the plough layer but can extend to soils of over 30 cm depths. We also need to revisit the general conventional view that no tillage can significantly reduce soil CO2 emissions compared with conventional tillage for better climate change mitigation.

Ratooning rice can efficiently utilize temperature and heat resources from the sun to increase multiple cropping index and grain yield while benefiting from one sowing and two harvests. Therefore, it is very important to rice production and food security in China. The high-yield germplasms of ratoon rice are the material basis for breeding varieties with strong ratooning ability. The lack of rice varieties with robust ratooning ability is a key factor restricting the development of ratoon rice. At present, the germplasm with strong ratooning ability is lack, and ratoon rice varieties are mainly selected from the varieties popularized in production. Therefore, it is important to apply direct breeding strategies to select for varieties of ratoon rice. The breeding technology of ratooning rice is continuously improving, and there are two methods to breed new varieties of ratoon rice. One approach is to employ combining ability to select for elite parents with strong ratooning ability and estimate the heritability of ratooning ability, which can be used to decide on selecting varieties or combinations with strong ratooning ability from its offspring. The second approach is to screen for characteristics closely related to ratooning ability of the 1st season rice. With the improvement of breeding technology, researching and solving the problem of rice ratooning ability from pedigree breeding and genetic effects will provide technical support and guarantee the direct breeding of new rice varieties with ratooning abilities. Using eight restorers applied in a large area of production as materials, directional selection and germplasm innovation were carried out by the pedigree method. In order to study the genetic characteristics of ratooning ability, the ratio of stems of ratooning bud to total stems were analyzed in a 4×4 incomplete diallel design by using the additive-dominant model. The results showed the following: (1) Genetic expression of ratooning ability was mainly controlled by both additive and dominant effects, but they were easily influenced by environmental conditions and cultivation techniques. (2) Predicted value of heritability of the ratooning ability traits were significant or extremely significant, and broad heritability ( h 2 B ) was significantly higher than broad heritability ( h 2 N ). (3) The ratooning ability was significantly different among rice restoring lines, and the ratooning ability traits of the restoring lines, Minhui 3301 and Yahui 627 had significant positive additive effects and negative dominant effects, which were suitable for screening parents with strong regeneration ability. (4) The new germplasm resources of Ra201, Ra202 and Ra212 had a higher ratio of stems of ratooning buds to total stems and strong ratooning ability, among which Ra202 had obvious advantages of low-node germination and could be used as parents for the gene mining and utilization of the ratooning ability in indica rice. (5) The study on breeding methods of ratoon rice cultivars has further improved the classical breeding techniques, and has the advantages of indirect identification and early screening. The effect of new germplasm creations and new breeding varieties were useful and insightful.

There is still limited information about the influence of different tillage and crop residue management on soil bacterial communities in the paddy field. Therefore, the short-term effects of tillag...

Ridge irrigation (RI) is a water-saving irrigation technique for paddy fields. To obtain a suitable mode of RI in increasing rice yield and reducing greenhouse gas (GHG) emissions from paddy fields...

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.

This study was designed to explore changes in soil bulk density, soil organic carbon content, soil organic carbon stock and soil labile organic carbon fractions under 34 years fertilizer regime in ...

Dairy farms have been under pressure to reduce negative environmental impacts while remaining profitable during times with volatile milk and commodity prices. Double cropping has been promoted to reduce negative environmental impacts and increase total dry matter yield per hectare. Three dairy farms that double cropped winter annuals and corn were selected from northern and western Pennsylvania. Data were collected from recorded crop and dairy records and financial data for 2016 and 2017. Farms ranged in size from 336 to 511 ha with 233 to 663 cows. Data were used to set parameters for the Integrated Farm System Model, which was then used to simulate 8 scenarios for each farm: current operation; 0, 50, and 100% of corn hectares double cropped; 30% feed price increase with and without double cropping; and 30% feed price decrease with and without double cropping at the farm's current level of double cropping. A 20-yr time period, using weather data that was representative of the actual farms, was used in the Integrated Farm System Model simulation to produce both financial and environmental outputs. Double cropping winter annuals and corn silage increased dry matter yield per hectare by 19%, when comparing 0 to 100% of the corn area double cropped. With all corn land double cropped, net return to management per hundredweight (45.36 kg) of milk increased by 1.8%, N leached per hectare per year decreased by an average of 4.5%, and phosphorus loss was reduced by an average of 9.2% across farms. When feed prices increased by 30%, double cropping increased net return over feed cost and net return to management by 1.6 and 2.2%, respectively, across farms. When feed prices decreased by 30%, double cropping decreased net return over feed cost and net return to management by smaller amounts of 0.13% and 0.11%, respectively, across farms. Modeling indicated that double cropping winter annuals with corn silage can have both environmental and economic benefits when winter-annual silage yields are enough to cover expenses.

Clarifying the characteristics of annual yield, distribution and utilization of climatic resources, and establishing rational quantitative indexes of annual climatic resources distribution for different cropping systems are helpful to provide theoretical basis for further improving annual yield and resource use efficiency in the Yellow-Huaihe-Haihe Rivers plain. In this study, the experiment was conducted from 2011 to 2015 at Xinxiang, Henan province to analyze the grain yield, biomass, dry matter production energy, and distribution and utilization efficiency of climatic resources under four cropping systems, namely winter wheat–summer maize, winter wheat–summer soybean, double maize and one–season spring maize. There were no differences in the annual grain yield, total biomass, and dry matter production energy between the winter wheat–summer maize and double maize cropping systems, but they were significantly higher than those of the winter wheat–summer soybean and one-season spring maize cropping systems, with an average increase of 45.4%–61.5%, 37.3%–71.3%, and 35.77%–70.7%, respectively. The annual radiation production efficiency, radiation use efficiency of grain and total biomass for double maize and one-season spring maize cropping systems were significantly higher than those of the winter wheat–summer maize and winter wheat–summer soybean cropping systems, with an average increase of 11.8%–66.7% in the annual radiation production efficiency, and 0.13–0.42 and 0.18–0.69 percentage points increase in the radiation use efficiency of grain and total biomass, respectively. The accumulative temperature distribution rate for two seasons of winter wheat–summer maize was 45.6% and 54.4%, respectively, while those of double maize was 51.4% and 48.6%, respectively. The accumulative temperature ratio between two seasons was of winter wheat–summer maize 0.8, while that of double maize was 1.1. Considering both yield and resource use efficiency, winter wheat–summer maize and double maize cropping systems can be used to optimize the layout of planting patterns and support the sustainable development of agricultural production in the Yellow-Huaihe-Haihe Rivers plain. Furthermore, clarifying the accumulated temperature distribution rate and the accumulated temperature ratio between two seasons is helpful to optimize climate resource distribution, and further improve the yield potential and the resources use efficiency of double cropping system in the Yellow- Huaihe-Haihe Rivers plain.

[EFFICIENCY OF LAND USE IN MULTIPLE CROPPING SYSTEM WITH VARIOUS CORN PLANT AND MUNG BEAN VARIETIES]. This study aims to find out the precise planting distance of corn with mung bean varieties that are suitable for increasing the efficiency of land use in terms of ecology and agronomy. Research has been carried out in the agricultural land in September 2018-January 2019 using a split-plot design. The main plot of planting spacing of corn which is 60 cm x 30 cm, 90 cm x 30 cm, and 120 cm x 30 cm, subplots ie mung bean varieties (Kutilang, Vima-1, Vima-2, Vima-3). As a comparison of intercropping systems, monocultures are cultivated by corn and mung beans. The results showed that in general intercropping of maize and mung bean NKL> 1, ecologically and agronomically efficient. However, this efficient level can be distinguished based on the spacing of corn and mung bean varieties. The best ecological efficiency at 120 cm x 30 cm corn spacing, while the best agronomic efficiency in Virna-3 mung bean varieties.

Background and objective Intercropping is one of the sustainable intensification methods which reduces the demand for increased land resources. However, growing of two or more crops as an intercrop is not business as usual but it needs extensive knowledge about the nature of component crops to grow in harmony. Hence selection and evaluation of compatible legume species for intercropping with finger millet in the study area is necessary. Materials and methods A field experiment was conducted at two major finger millet producing areas of northwestern Ethiopia. Four legumes crops such as (sweet lupine, cowpea, haricot bean, and soybean) intercropped with finger millet. Results The analysis of variance showed that intercropping of finger millet with different legumes had yield advantage in both districts as compared to component crops. Land equivalent ratio was more than unity for all treatments in both districts except for finger millet intercropped with soybean at South Achefer district. At Guangua finger millet + cowpea and finger millet + soybean showed 27% and 12% yield advantage, respectively and also finger millet + cowpea preferred first by farmers for its high grain yield, soil fertility improvement and its suitability for animal feed. At South Achefer finger millet + sweet lupine and finger millet + cowpea showed 38% and 35% yield advantage respectively and also finger millet + sweet lupine preferred first by farmers for its high grain yield to make stew as a protein source, soil fertility improvement and its suitability for human and animal feed. Conclusion Therefore intercropping, finger millet + cowpea and finger millet + soybean at Guangua and finger millet + sweet lupine and finger millet + cowpea at South Achefer preferred by farmers and also had yield advantage as compared to component crops. Hence finger millet + cowpea and finger millet + soybean recommended for Guangua and similar agro-ecologies and finger millet + sweet lupine and finger millet + cowpea for South Achefer and similar agro-ecologies as 1st, 2nd option respectively., Farmers’ preference; Finger millet; Legumes; Land equivalent ratio; Multiple cropping.

Different rice farming systems affect the soil microbial communities. Here, we report the results of 16S rRNA gene amplicon sequencing of soils collected from intensive rice cultivation and rice-shrimp farming systems in Soc Trang, Vietnam. The dominant phyla in these systems were Firmicutes , Actinobacteriota , Chloroflexi , Myxococcota , and Acidobacteriota .

Soybean (Glycine max (L.) Merrill) is very important crop for food, protein, and oil both human and animal feeding. The aim of this study determinate oil ratio, protein ratio and fatty acid compositions of Soybean breeding lines developed from Eastern Mediterranean Agricultural Research Institute (EMARI). This study was conductucted in double cropping system at the Eastern Mediterranean Agricul-tural Research Institute ( EMARI), Turkey in 2019 growing seasons. Through this study, it was realised that the fatty acid composition of soybean lines ranged from 11.34-9.80 for palmitic acid, 4.30-6.54% for stearic acid, 26.16-34.11% for oleic acid, 42.82-48.12% for linoleic, and 4.54-5.43% for linolenic acid in double cropped soybean. Oil content was found 22.4%, protein content was 40.9 % DA 12-14-3 and DA 12-15-39-40 soybean lines repectively.

Crop planting dates control the yield and cropping intensity of rainfed agriculture, and modifying planting dates can be a major adaptation strategy under climate change. However, shifts in rainfall seasonality may constrain farmers’ ability to adapt planting dates, and imperfect knowledge of how farmers currently select planting dates makes it difficult to predict how adaptations will proceed. This study analyzes variations in soybean planting and wet season onset dates across the agricultural state of Mato Grosso (MT), Brazil, for 2004 to 2014. It starts by exploring the strength of relationships between planting date and several precipitation-based definitions of the wet season onset, and shows that planting date is better correlated to easily observed onset definitions based on rainfall frequency than to climatological definitions. Next, a regression analysis shows that the sensitivity of planting dates to wet season onset exhibits large variations with cropping intensity and across farm fields, and that planting dates trended earlier over the study period, independently of onset variations. Finally, the results are used to predict soy planting dates in Mato Grosso under the RCP 8.5 climate scenario. Predictions show that planting dates will likely become delayed relative to preferred times, and that this may preclude double cropping in some parts of the state. This study demonstrates that the simple assumptions about farmers’ behavior often used in agricultural forecasting omit important spatio-temporal variations. Improved understanding of planting choices can reduce uncertainty in projected agricultural responses to climate change and highlight important areas for policy and agronomic adaptation.

Identifying the contributions of climate factors and soil fertility to crop yield is significant for the assessment of climate change impacts on crop production. Three 20-year field experiments were conducted in major Chinese wheat-maize cropping areas. Over the 20-year period, crop yield and soil properties showed significantly dissimilar variation trends under similar climate changes at each experimental site. The correlation between climatic factors and crop yield varied greatly among the fertilization regimes and experimental sites. Across all the fertilization regimes and the experimental sites, the average contribution rates of soil properties to wheat and maize yield were 45.7% and 53.2%, respectively, without considering climate factors, and 40.4% and 36.6%, respectively, when considering climate factors. The contributions of soil properties to wheat and maize yield variation when considering climate factors were significantly lower than those without considering climate factors. Across all experimental sites and all fertilization regimes, the mean contribution rates of climate factors to wheat and maize yield were 29.5% and 33.0%, respectively. The contribution rates of the interaction of climate and soil to wheat and maize yield were 3.7% and −0.9%, respectively. Under balanced fertilization treatments (NPK and NPKM), the change in the contribution rate of soil properties to wheat or maize yield was not obvious, and the average contribution rates of the interaction of climate and soil to wheat and maize yield were positive, at 14.8% and 9.5%, respectively. In contrast, under unbalanced fertilization treatments (CK and N), the contribution rates of soil properties to wheat or maize yield decreased, and the average contribution rates of the interaction of climate and soil were negative, at −7.4% and −11.2%, respectively. The above results indicate that climate and soil synergistically affected crop yields and that, with the optimization of the fertilization regime, positive interactions gradually emerged.

AIMS The potential nitrification activity (PNA), population size and community composition of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in paddy soil from a short-term (5 years) tillage field experiment conducted at tillering stage of late rice were investigated using the shaken slurry method and quantitative real-time polymerase chain reaction. METHODS AND RESULTS The experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue returning (NT) and rotary tillage with all crop residues removed as a control (RTO). The results showed that PNA in paddy soil of CT, RT and NT treatments was higher than that of RTO treatment, and the abundance of AOA and AOB was much higher in paddy soil of CT, RT and NT treatments than RTO treatment. Meanwhile, PNA and the abundance of AOB and AOA in paddy soil were greatly enhanced by combined application of tillage and crop residue, whereas PNA and the abundance of AOB and AOA in paddy soil were decreased by combined application of no-tillage and crop residue. Moreover, PNA was closely correlated with the abundance and community structure of AOB rather than AOA. The results also showed that PNA and the population sizes of AOB and AOA in crop incorporation treatments were higher than that of crop residue removed treatment. Cluster and redundancy analyses indicated that crop residue effect played a more important role in shaping AOA community structure compared to short-term tillage management. CONCLUSIONS The results indicated that AOB rather than AOA functionally dominated ammonia oxidation in the double-cropping rice paddy soil, the activities of AOB and AOA were increased and the community structure was also changed under the combination of conventional tillage, rotary tillage and crop residue condition. SIGNIFICANCE AND IMPACT OF STUDY The activity and community structure of AOB and AOA, which were affected by the combination of tillage and crop residue managements, play an important role in cycling of nitrogen.

In order to reveal the mechanism of microbial carbon (C) sequestration in paddy soil under different tillage management and to provide an important theoretical basis for perfecting the mechanism of C sequestration in paddy soil. C can indicate changes of soil nutrient content and soil microbial community, but more research is needed to study how C sources utilization characteristics respond to different tillage management under a double-cropping rice (Oryza sativa L.) paddy field in southern China. Hence, the impact of long-term (2005–2018) tillage management on utilization of microbial carbon sources in rhizosphere and non-rhizosphere soils under a double-cropping rice paddy field was studied by using 18O–H2O method in this study. The tillage treatments were included: (1) moldboard plow with all crop residue removed as a control (CT), (2) moldboard plow with all crop residue incorporated (CTS), (3) no-tillage with all crop residue retained on the soil surface (NTS), and (4) rotary tillage with all crop residue incorporated (RTS). The results indicated that Richness, Shannon, and McIntosh indices were increased by application of crop residue management, compared with treatment without crop residue, and soil microbial growth rate, soil microbial biomass C content, and soil microbial basal respiration with CT treatment were significantly lower (p

The field experiment was carried out at the Experimental Station of Vytautas Magnus University Agriculture Academy (Lithuania) in 2017–2019. The aim of the study was to determine and to compare weed spread and caraway crop productivity in sole (spring barley, spring wheat, pea, caraway), binary (spring barley-caraway, spring wheat-caraway, pea-caraway) and trinary (spring barley-caraway-white clover, spring wheat-caraway-white clover, pea-caraway-white clover) crops. In the second and the third years of caraway cultivation, it was estimated that the abundance of perennial weeds in the crops increased. In the first year, significantly the highest dry matter mass of weeds was determined in non-sprayed with herbicides binary crops with undersown caraway and in trinary crops with undersown caraway and clover, in the second year—in the caraway binary crops, when they were grown after barley and wheat without clover, in the third year—in caraway binary and trinary crops when they were grown after barley, wheat and pea without clover and after barley and wheat with clover. In the second year, the highest yields of caraway seeds were obtained by growing them in peas, and in the third year by growing them in wheat together with clover. Caraway can be grown in trinary crops, including white clover, and harvested in the second or the third year of the vegetative season.