International Journal of Plant Production
Volume:14 Issue: 3, Sep 2020

Climate change has had a considerable impact on potato production in Agro-Pastoral Ecotone (APE) in North China over the past several decades and it will continue to influence the growth of potato. Thus, understanding the impact of climate change on potato production is critical for future food security in this region. In this study, the calibrated APSIM-Potato model was used to assess the impact of future climate change on potato at Zhangbei (ZB) and Wuchuan (WC) experimental stations. The daily climate data were statistically downscaled from 32 global climate models under two Representative Concentration Pathways (RCP4.5 and RCP8.5). The results showed that potato yield under rainfed condition at ZB site respectively increased by 7.3% and 6.7% in the 2030s, 25.8% and 21.8% in the 2060s and 44.7% and 51.9% in 2090s under RCP4.5 and RCP8.5 scenarios. Potato yield under irrigated condition at WC site increased respectively by 5.5%, 10.0% and 15.1% in the 2030s, 2060s and 2090s under RCP4.5 scenario and by 5.7%, 20.9% and 41.1% under RCP8.5 scenario. Both evapotranspiration and water use efficiency increased under future climate change. Based on the statistical analysis, 70% of the variation in potato yield under rainfed condition at ZB site and 50% of it under irrigated condition at WC site were driven by future climate change. We concluded that rainfed potato yield will be enhanced more by future climate change than irrigation system. Our study filled the knowledge gap in understanding the potential effects of future climate change on potato production under different water management measures, and will be useful in developing adaptable strategies to enhance potato yield in the APE region under future climate change.

To establish the optimal fertilization rate to maintain high wheat yield and low environmental risk in the North China Plain, a two-year field experiment (2016–2018) was conducted with six combinations of two N rates (N0; N1: 240 kg ha−1) and three P rates (P0; P1: 150 kg ha−1; P2: 240 kg ha−1) to investigate the effects of these regimes on wheat grain yield, N assimilatory enzyme activity (nitrate reductase, NR and glutamine synthetase, GS), N use efficiency (NUE) and soil nitrate nitrogen distribution. Results showed that N application increased grain yield and grain protein concentration (GPC) significantly, in association with increased residual soil nitrate in both growing seasons, across the three P application rates. Only P application had no effect on these parameters. Significant interactions of N and P fertilizer were found on most of the tested parameters. Highest grain yield, GPC and NUE, and the lowest residual soil nitrate were observed under the treatment of N1P1. N accumulation in plant was highly correlated with grain yield and NUE, and N assimilatory enzyme activity at flowering was highly correlated with grain yield and GPC, which contributed to achieving high yield and NUE simultaneously. Regression analysis showed that the response of grain yield, NUE and residual soil nitrate to P rates fitted quadratic model, in which the maximum values of grain yield, NUE and the lowest residual soil nitrate were obtained at the extent of P rate 140 ~ 150 kg P ha−1. Hence, we recommended fertilizer rate of N 240 kg ha−1 and P 150 kg ha−1 as the optimal nitrogen-phosphorus regime in the North China Plain, which can maintain higher crop yield while lower environmental risk.

Quinoa is gaining importance globally owing to its nutritional quality and its adaptability under variety of conditions. However, limited information is available on the impact of planting techniques on growth, morphology, and yield and biomass accumulation under irrigation conditions. To the date, no ideal planting technique (sowing method) has been reported for the flat irrigated land for better adjustment of quinoa in a crop rotation. To test the hypothesis, a two-year field study (2013–14 and 2014–15) was carried out at University of Agriculture, Faisalabad, Pakistan. The experiment comprised of four planting technique bed sowing (BS), ridge sowing (RS), flat line sowing (FLS), and sowing in standing water (SSW) in main plots, and two quinoa accession (A7 and A9) in subplots. The results showed that BS method improved the morphological attributes viz. stem thickness, main panicle, main panicle, thousand grain weight, grain yield, and harvest index as compared to SSW. Regarding the quinoa accessions, A9 performed better than A7 for morphology, biomass, and yield. Panicle number per plant was positively correlated with harvest index and main panicle weight in 2013–14, while 1000-grain weight and harvest index had a stronger correlation during 2014–15. The average and maximum biomass production rate of A7 in BS plants were relatively higher than other sowing techniques either for A9 or A7. Our data suggest that the BS method is a relatively better planting technique and A9 quinoa accession is a suitable genotype to obtain a high targeted grain yield under irrigated conditions.

The reduction of the yield gap is one of the strategies implemented for the improvement of food security. In this research, the yield gap of wheat in the west of Golestan province, Iran, was estimated using a two-step methodology. In the first step, the potential yield was evaluated using the SSM-iCrop2 model and in the following, the yield gap was determined by the difference between the actual yield and potential yield. In the second step, the NDVI-actual yield regression in parallel with boundary-line analysis was used to assess the attainable yield. The estimated attainable yield varied from 3.0 to 5.8 t ha−1. Accordingly, the attainable yield gap in the studied region was 2.6 t ha−1 on average, which could be obtained via improved management. Also, based on model outputs, the potential yield varied from 5.4 to 7.2 t ha−1 which suggests a high possibility to improve wheat yield in the west parts of Golestan province. The results of the study provided basic information to quantify the yield gap and yield optimization options. Our results revealed that remote sensing in combination with crop simulation models is a powerful tool in regional assessments and removes the limitations of working with point data.

One of the most important forage crops in Iran is Alfalfa (Medicago sativa L.). Cultivar selection is important for alfalfa hay production. This research was carried out in 2017 and 2018 to assess the effects of harvest time and cultivar on growth, physiological traits and yield of alfalfa in saline condition. These field experiments were carried out at the Research Farm of East-Azarbaijan Agricultural and Natural Resources Research and Education Center, Tabriz, Iran (Firuz Salar village located 4 km from Azarshahr city). Results showed that the synthetic cultivars (C2 and C3) and especially C4 (Azar cultivar) has the highest forage yield and it attributed to high chlorophyll content, catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) activities, proline content, leaf area index (LAI), stem diameter, plant height and leaf to shoot ratio in these cultivars. However, the highest malondialdehyde (MDA) content related to C1 cultivar (Gara-Yonjeh as a local cultivar). Maximum of fresh and dry forage yields were achieved in second and third harvest times and it have related to high chlorophyll content, enzyme activities (CAT, POD and SOD), LAI, stem diameter, plant height, leaf to shoot ratio, proline and MDA contents in these harvest times. The highest acid detergent fiber (ADF), neutral detergent fiber (NDF), protein content and digestibility were obtained from C4 followed by C3, C2 and C1 cultivars. Value of ADF, NDF, protein content and digestibility were more during early harvests (H1 and H2) than during last harvests (H3 and H4). These findings have shown that suitable harvesting time of forage alfalfa is second stage for high yield and first stage for high quality. Synthetic cultivars and especially Azar cultivar was a superior cultivar. Thus, harvest time and cultivar selections can influence the yield and quality of alfalfa.

The occurrence of diseases in rice, mainly rice blast (Magnaporthe oryzae), is the main cause of yield reduction, and it has been controlled with the abusive use of fungicides in the conventional production system. To produce rice in an agroecological system, some measures, such as biological control, facilitates the transition from one system to another. The biological agent C24G classified as Cladosporium cladosporioides has been isolated from the phylloplane of rice plants and is a potential antagonist to rice pathogens. The aim of this study was to verify the efficiency of C. cladosporioides C24G under field conditions, in an agroecological system. During two growing seasons, C. cladosporioides was tested in a randomized block design in 4 replicates. The treatments consisted of: microbiolized rice seeds with C. cladosporioides, plant sprayed (2 applications), microbiolized rice seeds with C. cladosporioides + plant sprayed (2 ap.), plant sprayed (8 ap.) and microbiolized rice seeds with C. cladosporioides + plant sprayed (8 ap.) and control (no microbiolization and no spray). We evaluated leaf and panicle blast severity, physiological parameters associated with gas exchange, and grain yield. Leaf and panicle blast suppression was up to 85.58% and 79.63% in growing season 2016/2017, respectively, and 83.06% and 74.98% in growing season 2017/2018. At growing season 2016/2017, we observed an increase of the following parameters: photosynthetic rate (A) of 70.99% and 53.52% and transpiration (E) of 22.98% and 59.73% at vegetative and reproductive stage respectively, stomatal conductance (gs) of 126.66% at reproductive stage, water use efficiency (WUE) was up to 55.29% at vegetative stage, biomass 34.56% and yield 51.30%. At the growing season 2017/2018, we observed an increase at the photosynthetic rate (A) of 29.71%, at reproductive stage, biomass, 89.40%, and yield, 34.19%. We conclude that the treatments, microbiolized rice seeds or plant sprayed, allows the insertion of C. cladosporioides into the agroecological system, facilitating the agroecological transition with considerable grain yield, and leading to a final product without residues.

Multipurpose intercropping, as a way of agricultural intensification, would contribute to solving the food and feed shortage problems facing the developing countries. In Northern Egypt, a 2-year field study was conducted to investigate the forage potential, in terms of productivity and quality, of thinned sunflower and soybean intercrops, that were subjected to three nitrogen (N) fertilizer rates (70, 105, 140 kg N ha−1) and three ages at forage removal (thinning); 15, 30, and 45 days after sowing (DAS) for sunflower, and 30, 45, and 60 DAS, for soybean. Altering N rate exerted limited effect on the studied sunflower and soybean forage parameters. Dry matter (DM) content of sunflower (157.14 g kg−1) and crude protein (CP) content of sunflower (120.48 g kg−1) and soybean (162.49 g kg−1) were significantly increased, while soybean NDF content significantly decreased, with increasing the N rate. The effect of age at forage removal was more pronounced as it is a direct reflection to the crop’s stage of maturity at cutting. Older sunflower and soybean plants were characterized by higher herbage yield, DM and fiber contents, yet lower CP than younger plants. Maximum herbage yield achieved with late cutting of sunflower and soybean amounted to 9.82 and 10.81 t ha−1, respectively. Relative feed value of sunflower and soybean herbage was less stable in response to the variations in the studied treatments, while, relative forage quality resulting from all treatments was graded as “premium”, making them suitable for high-producing dairy cows and young calves in intensive dairy production systems.

Hidden hunger is emerging as a major challenge for agricultural scientists because world population is increasing and food production is augmenting. Metals deficiencies (micronutrient malnutrition), especially Zn and Fe, are affecting over half of global population because they are depending cereal crops mainly wheat rice and maize for their daily diet. There are various possible techniques to overcome the hidden hunger but agronomic biofortification is one of the major agricultural strategies to enhance the grain concentration of micronutrients. Application of iron sulphate (FeSO4) zinc sulphate (ZnSO4) and as alone or in combination either soil and foliar application increased the height of plants, number of tillers, spike length, number of spikelets per spike, number of grains per spike, thousand grain weight, economical yield, biological yield and harvesting index, calcium, magnesium, iron, zinc, copper and protein contents. Among different Zn and Fe concentrations applied either soil supplement or foliar spray, combine foliar spray of 0.5% ZnSO4 and 1% FeSO4 significantly improved the maximum growth or quality attributes of wheat. Biofortification is one of the major agricultural strategies to enhance the concentration of micronutrients in grains to minimize the malnutrition. Combination of Zn and Fe as foliar spray (0.5% ZnSO4 and 1% FeSO4) increased the yield traits of wheat crop as well as quality parameters of grains. Foliar application method is more appropriate for availability of nutrients to plants for optimum growth as compared to soil application method. Combined application of Zn and Fe (0.5% ZnSO4 and 1% FeSO4) through foliar spray is recommended to enhance the productivity of wheat crop with good quality of grains.

Sugarcane (Saccharum officinarum L.) yield is affected by climate, soil and management. The main approach used in Brazil defines the suitable area for growth considering soil and climate data, without considering the capacity of local management in reducing yield-limiting factors. Thus, the aim of this study is to characterize homogenous areas using sugarcane actual yield, climate, total plant-available soil water capacity (TASW), and production intensity data. The study was conducted in the Goiás state, totalizing 246 counties. The first step was to group areas based on actual yield obtained from 1973 to 2016. The groups were characterized considering climate (rainfall and air temperature), soil (TASW), and sugarcane production data. Actual sugarcane yield formed eight homogenous groups, numbered 1–8, containing 12 and 50 counties each group. The counties groups with a higher yield have a higher production intensity. They are near mills, have a higher TASW, and are divided in traditional and recent expansion areas. The counties groups with a lower yield have a lower TASW and a higher air temperature. Hotter regions are in the western and northern state border. New areas of expansion were available near current sugarcane mills within areas with a higher TASW. Thus, preferential regions were defined by associating edaphoclimatic conditions with high yield. These areas can receive support to improve sugarcane production.

The regional differences for responses of winter oilseed rape yield to climate changes was not reported in China, and the statistical climate–yield relationships at the provincial scale in south China should be a valuable attempt. With using provincial data of climate variables and oilseed rape yields during 1978–2016, the main findings were as follows: (1) based on 14 provincial climate-induced yield index (CIYI) series for oilseed rape yield, south China could be divided into five sub-regions with different temporal variations in CIYI by using principal component analysis, and they were Yangtze River delta (Region I), central south China (Region II), southwest China (Region III), southernmost China (Region IV) and southeastern coast (Region V), respectively; (2) the correlation and regression analysis between CIYI and monthly climate variables indicated that the precipitation of April, average potential evapotranspiration of November, average potential evapotranspiration of October, average mean temperature of May, and average potential evapotranspiration of September were the key climate variables (KCV) affecting yield in Region I, II, III, IV and V, respectively; (4) among the five sub-regions, the impacts of KCV changes on yields in southwest China were more notable, and the increasing trend of average potential evapotranspiration of November caused the decrease of yield by 2.08% in 1990s and 4.24% after 2000, respectively. These results could be employed as references for the assessment and mitigation of agro-meteorological disasters in south China.

The release of environmental pollutants, which partly emanates from the application of chemical inputs, is a major global concern. Attempt to determine the methods to reduce environmental risk of rice cultivation are required. Selecting the best cover crop in rice rotation is necessary. The novelty of this research versus current knowledge is that life cycle assessment (LCA) has not been applied to assess the environmental impacts of crop rotation systems in paddy fields in Iran. Hence, the life cycle of rice cultivars in different crop rotations was assessed in Neka region, northern Iran from 2017 to 2018. All the management practices/inputs of local (‘Tarom Hashemi’) and improved (‘Shiroodi’) rice cultivars were monitored. After recording the data of 100 selected paddy fields for each cultivar, nine cover crop-rice rotations (fallow-rice, clover-rice, rape seed-rice, wheat-rice, barley-rice, faba bean-rice, garlic-rice, lettuce-rice and cabbage-rice) were identified. Functional unit of LCA was 1-ton rice yield. The results demonstrated that the maximum and minimum amount of nitrogen, phosphorus and potassium were applied in fallow-rice and clover-rice rotations, respectively. The highest paddy yield for local (4856 kg ha−1) and improved (7745 kg ha−1) cultivars was produced in clover-rice rotation. Fossil CO2 eq, biogenic CO2 eq, global warming potential (GWP) 100a, terrestrial acidification (TA) and fossil depletion (FD) of local cultivar were 11.79%, 34.76%, 13.35%, 15.48%, and 20.13% greater than improved cultivar. The most cumulative energy demand (CED) in both cultivars was obtained for fallow-rice rotation followed by rape seed-rice rotation. The highest emission of biogenic CO2 eq for both cultivar was observed in rape seed-rice and fallow-rice rotations. The lowest amount of GWP 100a was calculated in clover-rice rotation for local and improved cultivars (248.08 and 240.5 kg CO2 eq). In both cultivars, the most and lowest amount of TA, freshwater eutrophication (FEU), ozone depletion (OD) and FD was emitted in fallow-rice and clover-rice rotations. Among the crop rotations, clover-rice and fallow-rice had significantly lowest and most emission of heavy metals in the air, water and soil, respectively. As a matter of fact, the environmental emissions of the study is straightly linked to the application of inputs and field management practices. According to this, the lowest amount of environmental emissions for both cultivars was observed in clover-rice rotation. The emissions released from environmental pollutants are positively correlated with the application of inputs and field management practices for crop species in rotation system. In conclusion, clover-rice rotation showed the potential to save non-renewable energies (fuel, nitrogen, and etc.) with higher paddy yield which is considered to be environmentally friendly crop in rotation with respect to reduce emissions of GHG.

An increase in the area under soybean and other legume crops in Europe is one of the assumptions of the European Soya Declaration. A study was undertaken to evaluate the influence of cropping system and tillage system on yield, some quality characteristics of soybean seeds and economic evaluation. Therefore, this paper is of interdisciplinary nature. On average over a four-year study period, the soybean seed yield was significantly higher in monoculture compared to the yield obtained in crop rotation. A decreasing trend in yield of monocultured soybean was only observed in the 4th year of the experiment. Seeds grown in monoculture were characterized by a significantly higher percentage protein content and a lower fat content compared to obtained in crop rotation. Plough tillage affected more beneficially soybean yield. Under no-tillage conditions, soybean seeds were shown to have a higher percentage protein content and a lower fat content. The average income per ha of soybean grown under plough tillage system was higher by EUR 64.6 than that under no-tillage. In comparing production profitability depending on the cropping system, it can be noted that it was more beneficial to grow soybean in monoculture. In monoculture, both plough tillage and no-tillage generated a higher income per ha than in the case of soybean grown in crop rotation.