Multiple Cropping Systems Research Articles

Characterization of early maturing elite genotypes based on MTSI and MGIDI indexes: an illustration in upland cotton (Gossypium hirsutum L.)

BackgroundGlobally, the cultivation of cotton is constrained by its tendency for extended periods of growth. Early maturity plays a potential role in rainfed-based multiple cropping system especially in the current era of climate change. In the current study, a set of 20 diverse Gossypium hirsutum genotypes were evaluated in two crop seasons with three planting densities and assessed for 11 morphological traits related to early maturity. The study aimed to identify genotype(s) that mature rapidly and accomplish well under diverse environmental conditions based on the two robust multivariate techniques called multi-trait stability index (MTSI) and multi-trait genotype-ideotype distance index (MGIDI).ResultsMTSI analysis revealed that out of the 20 genotypes, three genotypes, viz., NNDC-30, A-2, and S-32 accomplished well in terms of early maturity traits in two seasons. Furthermore, three genotypes were selected using MGIDI method for each planting densities with a selection intensity of 15%. The strengths and weaknesses of the genotypes selected based on MGIDI method highlighted that the breeders could focus on developing early-maturing genotypes with specific traits such as days to first flower and boll opening. The selected genotypes exhibited positive genetic gains for traits related to earliness and a successful harvest during the first and second pickings. However, there were negative gains for traits related to flowering and boll opening.ConclusionThe study identified three genotypes exhibiting early maturity and accomplished well under different planting densities. The multivariate methods (MTSI and MGIDI) serve as novel approaches for selecting desired genotypes in plant breeding programs, especially across various growing environments. These methods offer exclusive benefits and can easily construe and minimize multicollinearity issues.

MODELING THE EFFECTS OF PESTS AND PESTICIDE ON CROP YIELDS IN A MULTIPLE CROPPING SYSTEM

Pest infestation poses a significant threat to agricultural crop yields, and to control it, farmers spray chemical pesticides. The persistent use of these chemical agents not only leads to pesticide residues within crops but also exerts collateral damage on the beneficial pest population. In this research work, we formulate a nonlinear mathematical model to assess the impacts of pesticide on crop yields within a multiple cropping system. Model analysis illustrates that crop consumption rates destabilize, and the spraying rate of pesticide stabilizes the system. Furthermore, we determine conditions for the global stability of the coexisting equilibrium and conduct a global sensitivity analysis to identify model parameters that significantly influence pest population density. Our findings emphasize that, for effective pest population control and enhanced crop yields, farmers should choose either pesticides with a high pest abatement rate or those with a higher pesticide uptake rate. Considering the spraying rate of pesticide as time-dependent, we also suggest an optimal control strategy to minimize the pest population and associated costs. We provide analytical results backed by numerical simulations implemented through the non-standard finite difference scheme to support our findings.

Green manure removal with reduced nitrogen improves saline-alkali soil organic carbon storage in a wheat-green manure cropping system

The incorporation of green manure into cropping systems is a potential strategy for sequestering soil carbon (C), especially in saline-alkali soil. Yet, there are still unknown about the substitution impacts of green manure on nitrogen (N) fertilizer in wheat-green manure multiple cropping system. Herein, a five-year field experiment was performed to determine the impact of three levels of N fertilizer inputs [i.e., N fertilizer reduced by 0 % (100N), 10 % (90 N), and 20 % (80 N)] with aboveground biomass of green manure removal (0GM) and return (100GM) on soil organic carbon (SOC) storage and its primary determinants. The results demonstrated that no significant interaction on SOC storage was detected between green manure and N fertilizer management. 80 N enhanced SOC storage in bulk soil by 7.4 and 13.2 % in 0–20 cm soil depth relative to 100 N and 90 N (p < 0.05). Regardless of N fertilizer levels, compared with 100GM, 0GM increased SOC storage in bulk soil by 14.2–34.6 % in 0–40 cm soil depth (p < 0.05). This was explained by an increase in soil macro-aggregates (>2 and 0.25–2 mm) proportion contributing to SOC physical protection. Meanwhile, the improvement of SOC storage under 0GM was due to the decrease of soil C- and N-acquisition enzyme activities, and microbial resource limitation. Alternatively, the variation partitioning analyses (VPA) results further suggested that C- and N-acquisition enzyme activities, as well as microbial resource limitation were the most important factors for SOC storage. The findings highlighted those biological factors played a dominant role in SOC accumulation compared to physical factors. The aboveground biomass of green manure removal with N fertilizer reduced by 20 % is a viable option to enhance SOC storage in a wheat-green manure multiple cropping system.

Greenhouse Gas Emissions, Carbon Footprint, and Grain Yields of Rice-Based Cropping Systems in Eastern China

A multiple cropping system is beneficial for utilizing natural resources, while increasing the grain production and economic outputs. However, its impact on greenhouse gas emissions is unclear. The objective of this study was to evaluate the influence of rice-based cropping systems on methane (CH4) and nitrous oxide (N2O) emissions, the carbon footprint (CF), grain yields, and net economic returns in eastern China. Four treatments were applied: rice–fallow (as a control), rice–milk vetch, rice–wheat, and rice–rapeseed. Methane and N2O emissions were measured every 7 days via static chamber and gas chromatography methods from the 2019 rice season to the 2021 non-rice season. The CF was calculated based on the life cycle assessment. The results showed that multiple cropping systems significantly increased the annual grain yield by 1.2–6.4 t ha−1 and the annual CH4 and N2O emissions by 38–101 kg CH4-C ha−1 and 0.58–1.06 kg N2O-N ha−1, respectively. The average annual net returns for rice–wheat and rice–rapeseed were 131–150% greater than those for rice–milk vetch and rice–fallow. The annual CFs increased in the following order: rice–wheat (19.2 t CO2-eq ha−1) &gt; rice–rapeseed (16.6 t CO2-eq ha−1) &gt; rice–milk vetch (13.9 t CO2-eq ha−1) &gt; rice–fallow (11.5 t CO2-eq ha−1). The CH4 emissions contributed to the largest share of the CF (60.4–68.8%), followed by agricultural inputs (27.2–33.7%) and N2O emissions (2.9–5.9%). Moreover, nitrogen fertilizer accounted for 65.6–72.4% of the indirect greenhouse gas emissions from agricultural inputs. No significant difference in the CF per unit grain yield was observed between the four rice-based cropping systems. The CF per net return of rice–wheat and rice–rapeseed significantly decreased by 37–50% relative to that of rice–fallow and rice–milk vetch. These findings suggest the potential to optimize rice-based cropping systems for environmental sustainability and grain security.

Prospects of maize-faba bean intercropping in monocropping highlands of Ethiopia.

Abstract Intercropping is an environmentally sustainable multiple cropping system widely practiced in small-scale farming communities in developing countries. Despite its high yielding potential, modern agriculture exploits the scarce agricultural land resources and contributes to the loss of biodiversity whilst intercropping diversifies species, increases and stabilises yield, and ensures food security. Maize-legume intercropping is a dominant cropping system in Ethiopia particularly in the lowlands but not common in the highlands where monocropping of small cereals is a traditional practice. It not only has the potential to break the disease cycle but can also be an additional source of income and food. This study was designed to evaluate the effects of proportion and arrangement of maize and faba bean intercrops on land use, cumulative yield and economic return. Here we show that intercropping increases cumulative productivity and profitability over years and ensures sustainability. Maize yield increased by 59% and 84% in the second and third years, respectively, while yield of faba bean declined by 67% in the second and third years. Sole maize had lower and sole faba bean had higher than their intercropping yields. The highest total LER of 2.11 was obtained from 100% maize: 75% faba bean combination which was equivalent to an additional 1.11 ha of land allocated to sole cropping. Overall, we recommend 100% maize: 25% faba bean for resource-limited farmers and 75% maize: 100% faba bean for commercial farmers based on the monetary advantage index. Moreover, 100% maize: 75% faba bean with acceptable monetary advantage was recommended for the commercial farmers.

Environmental Impact Assessment of Rice–Wheat Rotation Considering Annual Nitrogen Application Rate

Rice–wheat rotation is a widely adopted multiple-cropping system in the Yangtze River Basin, China. Nitrogen (N) fertilizer is a key factor in regulating crop yield; however, only a few studies have considered the impact of annual N application on the yield, environmental impacts, and economic profits of rice–wheat rotation systems. In this study, a field experiment was conducted in the Jiangsu Province from 2020 to 2022. The rice and wheat seasons included six and five N fertilizer application rates, respectively (Rice: 0, 180, 240, 300, 360, and 420 kg N ha−1; Wheat: 0, 180, 240, 300, and 360 kg N ha−1), combined to form a total of 30 treatments. Life-cycle assessment was used to evaluate the environmental impacts of rice–wheat rotation under different N application treatments, using area, yield, and economic profit as functional units. Ten environmental impact categories were selected, including global warming. The results showed that grain yield did not consistently increase with an increase in N application, and the annual yield was the highest when 300 and 240 kg N ha−1 (R300W240 treatment) was applied in the rice and wheat seasons, respectively. The area-based weighting index of the R300W240 treatment ranked 20th among the 30 treatments, while the yield- and profit-based weighting indices were the lowest among the 30 treatments, decreasing by 14.9% and 28.7%, respectively, compared to the other treatments. The R300W240 treatment was the optimal annual N application strategy for rice–wheat rotation. Among the 10 environmental impacts considered, urea production contributed significantly to over eight environmental impacts, whereas the pollutant losses caused by its application contributed significantly to six environmental impacts. These findings reveal the dependence of the rice–wheat rotation system on the unsustainable use of N fertilizer and indicate that N fertilizer management practices should be further optimized to improve the environmental sustainability of grain production in the future.

Shifts in Soil Bacterial Communities under Three-Year Fertilization Management and Multiple Cropping Systems

The current study was undertaken to investigate how organic and inorganic fertilizers shape soil bacterial communities and soil nitrogen and carbon status and to find their relationships with plant production. Soils were collected from fields under a three-year application of green manures (vetch (GMV), field bean (GMB), and wheat (GMW)), livestock manure (MF), inorganic mineral fertilizer (IF), and control (no nitrogen fertilization). The plants cultivated during the three years were tomato, watermelon, and pepper, respectively. The findings showed an increase in crop yields under both organic and inorganic fertilizers, in which the effects of leguminous green manures (GMV and GMB) were more pronounced, equal to +65–81% in tomato, +32–40% in watermelon, and +51–57% in pepper. An extensive modification in the bacterial communities was observed under organic fertilization. These changes were associated with a higher ratio of Proteobacteria (a copiotrophic phylum) to Acidobacteria (an oligotrophic phylum) in GMV and GMB, due to higher soil N content compared to IF and control treatments. Therefore, the data indicated an increase in soil N and organic C levels, as well as higher plant production by replacing IF with GMV, GMB, and MF, suggesting a promising movement to preserve the soil ecosystem. Such changes were more pronounced in MF-treated soils, where bacterial diversity improved and the heterogeneity of bacterial communities was preserved.

OPTIMALISASI LAHAN BUDIDAYA PERTANIAN DENGAN SYSTEM MULTICROPPING SEBAGAI AGROWISATA EDUKATIF DI WONOGIRI

Indonesia is an agricultural country where the agricultural sector plays an important role in supporting national economic growth in the era of globalization, Land is one of the important indicators for the agricultural process, the effectiveness of land in each region is different. This study aims to describe the development of optimization of agricultural cultivation land with the Multiple Cropping system. The purpose of this optimization is the combination of cultivation of food crops and horticultural crops or called integrated agriculture on a certain economic scale, the cultivation process needs to be carried out with the correct technology support pattern and Standard Operating Procedure (SOP). This research uses qualitative research methods. Data collection techniques using interviews, observation and documentation. Data analysis uses qualitative descriptive analysis techniques. This study was conducted at Barro Tani Manunggal Agritourism. The results of this study show that land optimization techniques with multiple cropping systems are very effective to be applied in various land conditions, and can also be a business field for farmers.

Can the transition of multiple cropping systems affect the cropland change?

CONTEXTIntensification of cropland can achieve food security by increasing agricultural production pre-unit yield, thereby slowing down cropland expansion. However, it is also possible to accelerate the cropland expansion due to the increasing net benefits of cropland. The transition of multiple cropping system (MCS) caused by climate change is an important strategy for cropland intensification, its impact on cropland changes needs further in-depth discussion. OBJECTIVEThis research aims to address the following two questions: (1) The transition patterns of the MCS in China against the background of climate change; (2) The impact of the MCS's transition on the change rate of cropland and grain production capacity. METHODSBased on meteorological observation data, the Global Agro-Ecological Zones (GAEZ) model is utilized to map the China's MCS to analyze the temporal and spatial variation patterns of MCS under the comprehensive influence of various meteorological factors. On this basis, we investigate the change of cropland area and grain production capacity under the transition of MCS. RESULTS AND CONCLUSIONSThe results indicate that in the past 20 years, the increase of cropping intensity in China has led to 0.42Mha expansion in the multiple cropping area. Temporally, the probability of maintaining the original cropping system (2000) in 2020 was greater than the probability of transiting (83% > 17%). These transitions occurred more frequently between cropping systems with small gradation differences, and the probability of cross-gradation changes decreased with increasing cropping intensity. Spatially, the MCS exhibited a decreasing trend with increasing distance from the coastline. Although regardless of whether the MCS transiting or maintaining, the cropland area would reduce, the increase in cropping intensity would reduce the cropland area more than the decrease (6.48% > 2.66%). Moreover, we found that the decreased cropping intensity was beneficial to slow down the cropland reduction (4.35%; 2.93%; 5.95% > 2.66%), while increased cropping intensity accelerated the cropland reduction (1.56%; 4.35%; 2.93%; 5.95% < 6.48%). This result was further validated by grid-based statistical regression results (p < 0.05). In regions where the MCS transited, 96% of the cropland decrease was occupied by construction land, and 76% of the cropland expansion was due to the conversion of grassland. Among them, when the cropping intensity increased, although the cropland area reduced even more, the grain production capacity would actually increase by 40.29%, and when the planting intensity decreased, the grain production capacity would decrease by 10.55%. SIGNIFICANCEIncreasing the cropping intensity of cropland through multiple cropping can increase the comprehensive grain yield under the condition of limited cropland resources. This strategy holds significant promise for bolstering China's food security and fostering sustainable agricultural development.

Yield Comparison of Groundnut (Arachis hypogaea L) and Corn (Zea mays L) Under Sole and Multiple Cropping Systems

Yield Comparison of Groundnut (Arachis hypogaea L) and Corn (Zea mays L) Under Sole and Multiple Cropping Systems

Invasion of fall armyworm, (Spodoptera frugiperda, J E Smith) (Lepidoptera, Noctuidae) on onion in the maize–onion crop sequence from Maharashtra, India

IntroductionClimate change affects geographical distribution of insect pests which poses threats to the environment, as well as agricultural productivity and production worldwide. Spodoptera frugiperda is commonly known as fall armyworm (FAW), a potential insect pest of monocot crops like maize, wheat, rice and sorghum globally. Among these, maize is the most preferred host crop while worldwide there are very few reports on onion being a host of fall armyworm.MethodsThe fall armyworm (FAW) was identified by examining the morphological characteristics of its immature and mature stages, as well as by analyzing the mitochondrial cytochrome oxidase 1 (COX1) gene. Further, the strain identity was confirmed through multiple sequence alignment with previously identified S. frugiperda strains from corn and rice. Also studied the biology and damage symptoms caused by FAW in onion crops.ResultsDuring our experiments, the incidence of FAW ranged from 5 to 20 percent in different plots. The highest incidence was observed in young crops (30–45 days after transplanting) that were sown in November 2020. The FAW larvae exhibited six instars, with a total larval duration of 22.2 ± 0.37 days. The pest had multiple generations per year. The fully developed larvae formed earthen cocoons in the soil for pupation, with a pupal duration of 8.0 ± 0.45 days. The male adults had a recorded longevity of 6.4± 0.40days, while the female adults lived for approximately 9.2 ± 0.37 days. The COX1 gene sequencing revealed its 100% similarity with Spodoptera frugiperda and the comparison of sequences among FAW infecting rice and maize by using multiple sequence alignment showed differences at 11 positions.DiscussionThe present study is the first report of FAW invasion in onion in India and provides basic ideas about FAW characteristics which will help to control this new invasive pest in onion. In tropical regions with multiple cropping system and seasons, it becomes very important to investigate invasive pests as well as its host range in order to forecast its potential damage and devise suitable control measures.

Appraisal of Soil Conservation Practices Utilized by Crop Farmers in Orashi Region of Rivers State, Nigeria

This study investigated soil conservation practices utilized by crop farmers in Orashi Region of Rivers State consisting of Ogba/Egbema/Ndoni, Ahoada East and Ahoada West Local Government Areas. Data were collected using structured questionnaire based on 4-point Likert rating scale and interview schedule. A population sample of one hundred and twenty (120) respondents was selected to elicit information using the stratified sampling technique. Forty (40) crop farmers from each Local Government Area were selected for the study. Data were analyzed using descriptive and inferential statistics such as the arithmetic mean. Findings show that more than half (76.7%) were married and 45.8% had formal education. Majority of the respondents were within the ages of 40-49 years. The type of soil conservation practices adopted were application of manure ( =3.37), planting of cover crops ( =3.73), use of multiple cropping system ( =3.93), use of reduced tillage methods/direct seeding ( =3.83), bush fallowing ( =3.86), incorporation of crop residue ( =3.74), mulching ( =3.85), construction of bonds/other structures ( =3.93), shifting cultivation ( =3.54), and crop rotation ( =3.53). The level of adoption and utilization of the identified measures tends to agree with the farmer’s year of experience, level of awareness of soil conservation measures, age-long cultural practices or cultural barrier and technical knowhow. The study concluded that government should enact favourable agricultural policies that will enlighten farmers on soil conservation practices in their cultivation exercise. The services of extension workers will be helpful in this direction.

A large‐scale survey reveals agro‐ecological factors influence spatio‐temporal distribution and epidemics of maize leaf blight: Implications for prioritizing sustainable management options

AbstractIntroductionProductivity of maize (Zea mays L.) is predominantly constrained by diseases, weeds, and insect pests. The northern leaf blight (NLB) disease, caused by Exserohilum turcicum, inflicts significant maize yield losses in the tropics and humid tropics, including Ethiopia. A large‐scale field survey was conducted to assess the spatio‐temporal distribution of maize NLB in southern Ethiopia, and to determine the association of maize farming practices and agro‐ecological factors with NLB epidemics during 2016–2019.Materials and MethodsA total of 814 maize farms were assessed in 12 major maize‐producing districts. During the assessment, data related to the disease, crop, farming practices and agro‐ecological factors were collected. The associations of disease severity with independent factors were determined using the ordinal logistic regression model.ResultsThe results showed that all studied districts and zones recorded high (≥85%) NLB prevalence over the 4 years, and the disease continues to be a major threat to maize production. Variable disease severity was recorded across districts/zones during the study periods. The highest (75.45%) mean severity was recorded from Boreda, followed by Konso (75.36%), Bonke (71.61%) and Derashe (71.30%), while Mihirab Abaya (33.25%) and Arba Minch (38.285%) districts recorded the lowest mean severity. In the multiple regression model, zone, altitude, cropping year, land preparation, NPS fertilization, weeding practice, growth stage and cropping system were highly significantly (p &lt; 0.0001) associated with disease severity.ConclusionMaize cultivation at an altitude of ≤1500 m with intermediate to good weeding practices, recommended NPS (51–100 kg ha–1) fertilization, mixed‐ and intercropping systems, sparse plant (≤20 plants m‒2) population, and vegetative to blistering growth stages had significant relationships with low (≤25, 26%–50%) disease severity, and can be considered as management options to reduce NLB pressure and yield losses to sustainably ensure maize production and productivity.

Mapping Cropland Intensification in Ecuador through Spectral Analysis of MODIS NDVI Time Series

Multiple cropping systems constitute an essential agricultural practice that will ensure food security within the increasing demand of basic cereals as a consequence of global population growth and climate change effects. In this regard, there is a need to develop new methodologies to adequately monitor cropland intensification. The main objective of this research was to assess cropland intensification by means of spectral analysis of MODIS NDVI time series in a high cloudiness tropical area such as Ecuador. A surface of 89,225 ha of the main staple crops in this country, which are rice and maize crops, was monitored to assess the evolution of the number of crop cycles. The 20-year period of NDVI time series was used to calculate the periodograms across four subperiods (2001–2005, 2006–2010, 2011–2015, 2016–2020). The maximum ordinate value of each periodogram was used as an indicator of the number of growing crop cycles per year identifying single-, double-, and triple-cropping systems in each subperiod. Cropland intensification was assessed by comparing the cropping system between the subperiods. Results reveal that more than half of the studied croplands experienced changes in the cropping systems, and 40% showed positive trends in terms of the number of growing crop cycles, being principally located near the main rivers where irrigation facilitates crop development during the dry season. Therefore, the area under single cropping decreased from over 60,000 ha in the first subperiod to less than 50,000 ha in the last two subperiods. The cropland surface subjected to multi-cropping practices increased during the second decade of the study period, with a double-cropping system being more widely used than growing three crops per year, reaching surfaces of 24,400 ha and 10,450 ha in the last subperiod, respectively. The robust results obtained in this research show the great potential of the periodogram approach for the discrimination of cropping systems and for mapping intensification areas in tropical regions where dealing with noisy remote sensing time series as a consequence of high cloudiness is a great challenge.

Bulk density and soil porosity in the Patchouli development area of Aceh Barat, Indonesia

Good soil physical characteristics are of great importance to the growth of patchouli plants. This study aims to examine soil conditions analyzed by soil physics in patchouli development areas in Aceh Barat Regency because it is one of the patchouli development areas in Aceh Province. The research method used is a descriptive method, namely through field surveys and laboratory analysis. In this study, we focused on two physical characteristics of soil, namely bulk density (BD) and soil porosity. Soil samples were taken purposively at 15 patchouli planting sites in three sub-districts in Aceh Barat, namely of Woyla Barat, Woyla Induk, and Sungai Mas, each representing a monoculture, multiple cropping and mixed garden system. Each site was given five points of soil samples at a depth of 0–30 cm using sample rings. The results of the analysis showed that, in general, the bulk density (BD) of the soil is included in the weight category with BD values ranging from 1.27–1.30 Mg/m3, while the porosity of the soil is classified as rather poor to rather good with values ranging from 48.46–50.77%. From the analysis of the data obtained, it shows that the entire patchouli development area in West Aceh has relatively homogeneous soil physics characteristics from the aspect of soil physics and soil constraints are found in poor conditions. Therefore, to improve soil quality, it is necessary to add ameliorant materials, especially types of organic amendments such as compost, biochar, manure, and other supporting factors.

Intercropping as a multiple advantage cropping system: Review

Intercropping as a multiple advantage cropping system: Review

Can the cropping systems of the Nile basin be adapted to climate change?

Climate change poses a fundamental threat to agriculture within the Nile basin due to the magnitude of projected impacts and low adaptive capacity. So far, climate change impacts on agriculture for the basin have mostly been assessed for single-cropping systems, which may bias the results considering that the basin is dominated by different cropping systems, with about one-third of the crop area under double cropping. In this study, we simulate single- and double-cropping systems in the Nile basin and assess the climate change impacts on different cropping systems under two scenarios, i.e. “no adaptation” and “adaptation to a late-maturing cultivar”. We find that the mean crop yields of maize, soybean and wheat decrease with future warming without cultivar adaptation. We attribute this to the shortening of the growing season due to increased temperature. The decrease is stronger in all single-cropping systems (12.6–45.5%) than in double-cropping systems (5.9–26.6%). The relative magnitude of yield reduction varies spatially with the greatest reduction in the northern part of the basin experiencing the strongest warming. In a scenario with cultivar adaptation, mean crop yields show a stronger increase in double-cropping systems (14.4–35.2%) than single-cropping systems (8.3–13.7%). In this scenario, farmers could possibly benefit from increasing cropping intensities while adapting to late-maturing cultivars. This study underscores the importance of accounting for multiple-cropping systems in agricultural assessments under climate change within the Nile basin.

Cover crop by irrigation and fertilization improves soil health and maize yield: Establishing a soil health index

Cover crop can reduce the intensity of land use, and improve soil fertility and productivity in multiple-cropping systems. However, only a few studies have comprehensively evaluated soil health after cover crops in terms of management goal and soil multi-functionality. In this study, different minimum data set (MDS) methods were used to establish a soil health index (SQI) model to evaluate soil health of the winter smooth vetch-summer maize cropping system in southwest China. We analyzed thirty-five soil parameters (representing soil physical, chemical and biological properties) connected with the soil functions as potential soil health indicators in the phase of smooth vetch and maize under six management treatments (CK (control), N (N fertilizer), P (P fertilizer), NP (N and P fertilizer), NPW (N and P fertilizer + irrigation), CF (fallow)). Those managements were set in the smooth vetch phase (as a cover crop). The MDS using correlation analysis (cMDS), principal component analysis (pMDS) and random forest analysis (rMDS) from the total data set (TDS) were selected and then used for SQIs calculation, respectively. Cover crop by different management of irrigation and fertilization affected each soil property in different ways. All three SQIs were significantly correlated with SQI-TDS, validating the SQI models developed by three MDS methods (P < 0.05). Further, the SQI based on rMDS was the most accurate and sensitive, suggesting the RFA-based SQI reflects soil functions more adequately than the CA and PCA-based SQI. Cover crop by the management of fertilization or/and irrigation will not only improve soil health, but also enhance maize yield compared with fallow treatment, especially for NPW treatment. Fertilization treatments (N, P, NP and NPW) had higher soil health index, which was related to the better performance of soil in sustaining biological activity, physical stability and supporting function. In summary, the SQI model developed by the RFA method can provide a practical and robust tool for assessing soil health based on the management goal.

From multiple cropping frequency to multiple cropping system: A new perspective for the characterization of cropland use intensity

CONTEXTMultiple cropping is a widespread agricultural practice that can partly reflect cropland use intensity. Previous studies have largely focused on harvest frequencies within an annual (e.g., multiple cropping frequency [MCF]) or multiannual basis. However, the complexity of cropland use intensity, which combines different cropping and fallow strategies, has not been fully investigated. Moreover, such information is particularly lacking at the regional scale. OBJECTIVEThis study proposed a new perspective of multiple cropping system (MCS), and developed a method for mapping stable MCSs for a prolonged time. METHODSWe selected an agricultural region (Poyang Lake Plain, Jiangxi Province, China) and proposed four stable MCSs in terms of the number of crops (C) grown in a given number of years (Y) defined by the length of crop rotation: Continuous single-cropping system (1C/1Y), continuous double-cropping system (2C/1Y), and two alternating systems (3C/2Y and 5C/3Y). To map MCSs, we first obtained the remote-sensing-observed annual MCF from 2001 to 2018. Second, total harvests, frequency, and continuity were proposed based on multi-year MCF information to classify each pixel as one of the four proposed MCSs. Total harvests were defined as the total number of harvests over the observation period. Frequency was defined as the total number of rotation units over the observation period for a given MCS. We defined continuity as the largest number of consecutive years under a given MCS. Finally, we determined the final type of an MCS using decision rules considering the three indicators. RESULTS AND CONCLUSIONSThe results showed that the overall accuracy of the MCF maps were > 90%, and the overall accuracy of MCS map was 87.8%. We found that 84.4% of croplands could be characterized as one of the four MCSs: 2C/1Y accounted for the largest area (38.1%), followed by the two alternating systems (together they accounted for 48.6% of the total), and finally 1C/1Y. SIGNIFICANCEThe results of our study suggest that multiple cropping practices should be characterized from the cropping system perspective. The MCS mapping method has great potential for large-scale crop rotation system mapping, and the MCS mapping results could help explore the combined effects of different cropping systems and further provide strategies for optimizing the spatially adapted practices in agricultural land systems.

Reducing greenhouse gas emissions and improving net ecosystem economic benefit through long-term conservation tillage in a wheat-maize multiple cropping system in the Loess Plateau, China

Reducing greenhouse gas emissions and loss of soil fertility, while ensuring stable yield, is crucial to achieving “Carbon Peak” and “Carbon Neutrality” in grain production but is different to achieve. In this study, we aimed to understand the effects of conservation tillage on the yield, GHG emissions, soil carbon and nitrogen sequestration, and net ecosystem economic benefit (NEEB) to promote the transformation of tillage methods in the Loess Plateau, China, based the continuous application (>11 yr) of conservation tillage. Four-year observations showed that zero tillage and chisel plough tillage obviously reduced N2O and CO2 emissions but greatly increased CH4 uptake relative to plow tillage. Furthermore, the coupling relationship between CO2 and N2O fluxes was weakly antagonistic during the winter wheat growing season, whereas there was a strong synergistic coupling between these fluxes during the summer maize growing season. An antagonistic coupling relationship appeared between CH4 and N2O fluxes, whereas CO2 and CH4 fluxes appeared to be randomly related. Importantly, when carbon (C) emission reached 17.5 Mg C ha−1yr−1, and nitrogen (N) emission reached 7.8 kg N ha−1yr−1, the soil changed from a C sink to C source; when C emission reached 17.3 Mg C ha−1yr−1, and N emission reached 6.8 kg N ha−1yr−1, the soil changed from a N sink to N source. Considering yield gains, agricultural activity costs, and global warming potential costs together, chisel plough tillage significantly increased NEEB by 19.87%. Together, the advantages of long-term chisel plough tillage can reduce greenhouse gases emissions and increase NEEB while achieving soil carbon and nitrogen sequestration. Therefore, chisel plough tillage practice has both economic and environmental benefits.