Organic and inorganic fertilization influenced on yield and quality of sugar beet genotypes

The objective of this study was to evaluate the effects of organic and inorganic fertilizers on yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore a field trial was carried out at New Developmental Farm of The University Agriculture, Peshawar, Pakistan during winter 2012–13. The field experiment was layout in randomized complete block design with split plot arrangement having three replications. Fertilizers treatments (control, higo organic plus (composted manure, it contains N 2%, P 3%, K 3%, organic matter 40%, organic carbon 11%, Zn 145 mg kg^–1, Cu 56 mg kg^–1, Fe 380 mg kg^–1 and Mg 228 mg kg^–1), maxicrop sea gold (extract of sea weeds i.e., Sargasssum, Laminara Polysaccharide and Ascophyllum Nodosum), farm yard manure, NP (90: 60 kg ha^–1), NP (120: 90 kg ha^–1) and NP (150: 120 kg ha^–1) were allotted to main plots while genotypes (Sandrina, Serenada and Kawe Terma) to the sub plots. Farm yard manure (10 t ha^–1) and higo organic Plus (5 t ha^–1) was incorporated in the soil before seed bed preparation. Maxicrop sea gold (5 lit ha^–1) was sprayed after the emergence of the crop. All phosphorus was applied @ of 60, 90 and 120 kg ha^–1 at the time of sowing while nitrogen @ of 90, 120 and 150 kg ha^–1 in two splits/3 of the dose was applied at the time of sowing while the remaing 1/3 of the dose was applied before earthen up. Plots treated with application of NP ratio 120: 90 kg ha^–1 produced maximum beet yield (76.4 t ha^–1), sugar yield (11.1 t ha^–1), Pol (polarizable sugar) percentage (14.67%) and more economic return (Rs.234 Thousand ha^–1) as compared to control plots. Sugar beet genotype Serenada had significantly produced maximum beet yield (55.5 t ha^–1), sugar yield (7.9 t ha^–1), pol (polarizable sugar) percentage (14.60%), brix percentage (14.60%) and more economic return (158) as compared to other genotypes. It was concluded from the above results that sugar beet genotype Serenada treated with NP ratio 120: 90 kg ha^–1 for improved sugar beet productivity and quality therefore it is recommended for general practice in agro-climatic conditions of Peshawar valley.     

Ecological Environmental Variability Influence Growth and Yield Potential of Rice under Northern Climatic Scenario

To evaluate the response of various rice genotypes to environmental variability and fluctuation in temperature for growth and development of the plant, an experiment was conducted at Agriculture Research Institute (N) Mingora Swat, Pakistan, during summer 2011. The site is located at 34° and 36° North latitude and 72° and 73° East longitude and at an altitude of 975 m above sea level. Experimental site falls in temperate region where the average annual precipitation is ranges from 1000 to 1200 mm. Seven genotypes (PARC 403, OM5627, IR64, IR8225-9-3-2-3, CIBOGO, GA-5015, and Fakhre Malakand) were evaluated for growth and yield parameters in respect of seasonal variation of transplanting. Five transplanting dates, (D1 = 25th May, D2 = 9th June, D3 = 24th June, D4 = 9th July, and D5 = 25th July) were used during the study. Results divulge that optimum temperature for well growth and development was found on D2 (9th June), taken less number of days to 50% flowering (72), less number of days taken physiological maturity (112), produced taller plant height (88.62 cm), maximum tiller plant^–1 (20.3 cm), panicle length (22.0 and 22.0 cm), paddies panicle^–1(191 and 193), 1000 paddy weight (18.15 and 18.16 g) and paddy yield (5.65 and 5.53 t ha^–1) respectively. As the transplanting was delayed decreased in yield contributing parameters was noted. Panicle length (17.9 cm), paddies panicle^–1 (176.14) and paddy yield (4.12 t ha^–1) was observed when transplanting was done on D5, while D1 and D4 were at par valued in tiller plant^–1, Panicle length, 1000 paddy weight, and paddy yield respectively. Fakhre-e-Malakand was found best among the tested genotypes for early maturity, maximum plant height, highest tillers plant^–1 (22.2), panicle length (21.8 cm), paddies panicle^–1 (197.7), 1000 paddy weight (19.2 g) and paddy yield (6.49 t ha–1) under the northern climatic scenario.     

Determination of soybean yield gap and potential production in Iran using modeling approach and GIS

Increasing crop production is necessary to maintain food security for the growing global population.Reducing the gap between actual and potential yield is one of the important ways to increase yield per unit area.Potential yield and the yield gap of soybean were determined for Golestan Province,Iran,using Soybean Simulation Model (SSM-i Crop2) and Geographical Information System (GIS).Information from 24 weather stations and soil data of the region were used.Yield gap and production gap were calculated at county and province levels.The average actual yield of soybean in this province was2.28 t ha~(–1) while the province’s potential yield was 4.73 t ha~(–1),so the yield gap was estimated 2.44 t ha~(–1).Thus,there is a great potential for increasing soybean yield in Golestan,which is possible through improving crop management of soybean in farmers’fields.The average water productivity of soybean was estimated to be 0.81 kg m~(–3).Spatial distribution of water productivity in soybean farms showed that the highest and the lowest water productivities (0.99 and 0.44 kg m~(–3)) were in western and eastern regions of the province,respectively,in accordance to vapour pressure deficit.It was concluded that soybean production in the province could increase by 66%(from 109 970 to 182 170 tons) if 80% of the current yield gap could be removed.     

Effects of sowing date and ecological points on yield and the temperature and radiation resources of semi-winter wheat

Exploring the effects of sowing date and ecological points on the yield of semi-winter wheat is of great significance. This study aims to reveal the effects of sowing date and ecological points on the climate resources associated with wheat yield in the Rice–Wheat Rotation System. With six sowing dates, the experiments were carried out in Donghai and Jianhu counties, Jiangsu Province, China using two semi-winter wheat varieties as the objects of this study. The basic seedlings of the first sowing date (S1) were planted at 300×10⁴ plants ha⁻¹, which was increased by 10% for each of the delayed sowing dates (S2–S6). The results showed that the delay of sowing date decreased the number of days, the effective accumulated temperature and the cumulative solar radiation in the whole growth period. The yields of S1 were higher than those of S2 to S6 by 0.22–0.31, 0.5–0.78, 0.86–0.98, 1.14–1.38, and 1.36–1.59 t ha^–1, respectively. For a given sowing date, the growth days increased as the ecological point was moved north, while both mean daily temperature and effective accumulative temperature decreased, but the cumulative radiation increased. As a result, the yields at Donghai County were 0.01–0.39 t ha^–1 lower than those of Jianhu County for the six sowing dates. The effective accumulative temperature and cumulative radiation both had significant positive correlations with yield. The average temperature was significantly negatively correlated with the yield. The decrease in grain yield was mainly due to the declines in grains per spike and 1 000-grain weight caused by the increase in the daily temperature and the decrease in the effective accumulative temperature.     

Growth simulation and yield prediction for perennial jujube fruit tree by integrating age into the WOFOST model

Mathematical models have been widely employed for the simulation of growth dynamics of annual crops, thereby performing yield prediction, but not for fruit tree species such as jujube tree(Zizyphus jujuba). The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter. The model was established using data collected from dedicated field experiments performed in 2016–2018. Simulated growth dynamics of dry weights of leaves, stems, fruits, total biomass and leaf area index(LAI) agreed well with measured values, showing root mean square error(RMSE) values of 0.143, 0.333, 0.366, 0.624 t ha~(–1) and 0.19, and R~2 values of 0.947, 0.976, 0.985, 0.986 and 0.95, respectively. Simulated phenological development stages for emergence, anthesis and maturity were 2, 3 and 3 days earlier than the observed values, respectively. In addition, in order to predict the yields of trees with different ages, the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI), which was calculated as averaged, fitted and optimized values of trees with the same age. The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI. The modelling performance was significantly improved when it considered TDWI integrated with tree age, showing good global(R~2≥0.856, RMSE≤0.68 t ha~(–1)) and local accuracies(mean R~2≥0.43, RMSE≤0.70 t ha~(–1)). Furthermore, the optimized TDWI exhibited the highest precision, with globally validated R~2 of 0.891 and RMSE of 0.591 t ha~(–1), and local mean R~2 of 0.57 and RMSE of 0.66 t ha~(–1), respectively. The proposed model was not only verified with the confidence to accurately predict yields of jujube, but it can also provide a fundamental strategy for simulating the growth of other fruit trees.     

Canola yield and quality enhanced with sulphur fertilization

Canola cultivars positively responded to sulphur fertilization in term of seed yield and oil quality. Oscar cultivar increased seed yield 53% as compared to control plots. Sulphur @ 45 kg ha^–1 increased seed yield, biological yield, and quality of rapeseed. Number of days to flowering (76), number of pods plant–1 (372), number of seeds pod–1 (24), plant height (173 cm), biological yield (15547 kg ha^–1), seed yield (2209 kg ha^–1), harvest index (19%), glucosinolate (μmol g–1) content (31.03 μmol g–1) and oil content (45.81%) was enhanced significantly with sulphur treated @ 45 kg ha^–1 applied plots as compared to delayed flowering (78 days), shortest plant (151 cm), pods formation (298 pods), seed pod–1 (21), biological yield (11090 kg ha^–1), seed yield (1436 kg ha^–1), and oil content (42.62%) in control plots. Among cultivars “Oscar” ranked first in different growth stages and attain more plant height (164 cm), and examined substantial number of pods plant–1 (359), seeds pod–1 (24), seed yield (2005 kg ha^–1), biological yield (14298 kg ha^–1), harvest index 17%, and oil content (46.29%) as compared to other sowed cultivars. On the basis of the result it is recommended that cultivar “Oscar” treated with sulphur @ 45 kg ha^–1 should be applied for higher yield and quality of rapeseed under the agro-climatic condition of swat valley.     

Soil tillage methods by years interaction for dry matter of plant yield of maize (Zea mays L.) using additive main effects and multiplicative interaction model

The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha~(–1)(for no-plough tillage in 2005) to 246.4 dt ha~(–1)(for complete conventional tillage in 2012), with an average of 146.6 dt ha~(–1). In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.     

Does heat accumulation alter crop phenology,fibre yield and fibre properties of sunnhemp (Crotalaria juncea L.) genotypes with changing seasons?

Field experiments were carried out in split plot design during the dry and wet seasons for two years(two seasons each in 2016–2017 and 2017–2018) with two genotypes(SH4 and SUIN053), two plant geometry(30×15 cm and 45×15 cm main plots) and three levels of NPK(20 kg N ha~(–1), 40 kg P ha~(–1) and 40 kg K ha~(–1); 20 kg N ha~(–1), 60 kg P ha~(–1) and 60 kg K ha~(–1); 20 kg N ha~(–1), 80 kg P ha~(–1) and 80 kg K ha~(–1)) with an objective to study the relationship between fibre yield of sunhmep and thermal indices. The results indicated that the thermal units such as cumulative heat unit(CHU), photo thermal unit(PTU) and helio thermal unit(HTU) were the highest during dry seasons, while relative temperature disparity(RTD) was the highest during wet seasons irrespective of the genotypes, plant geometry and fertilizer levels. The combined analysis of variance showed that the suitability of sunnhemp genotypes for obtaining fibre and seed yields varied with season. The results further indicated that sunnhemp grew during dry seasons with longer photoperiod and higher values of growing degree days(GDD), HTU and PTU resulted in a higher fibre yield, while a higher seed yield and relatively longer, finer and stronger fibres were obtained during wet seasons with higher RTD values. Regression analysis indicated that CHU was positively related to fibre yield, while RTD was positively related to seed yield. CHU beyond 2 000 °C d reduced seed yield and favoured fibre production. In contrary to CHU, RTD values were positively related to seed yield and negatively related to fibre yield. Similarly, HTU had an inverse relationship with fibre yield while PTU had a positive relationship with fibre yield. The genotype SH4 produced a seed yield of 1 361 kg ha~(–1) during wet seasons, which was significantly higher than SUIN053, while a fibre yield of 990 kg ha~(–1)(significantly higher than that of SH4) was obtained for SUIN053 that required less CHU to attain the phenological events during dry seasons. The per unit area yields of seed and fibre with the closer spacing(30 cm×15 cm) by virtue of higher plant density were 17.0 and 14.9% higher than those with the spacing of 45 cm×15 cm, respectively. Higher doses of P and K resulted in higher seed and fibre yields.     

No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment

This study was conducted to determine whether, and if so how, the grain yield and nitrogen (N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage (NT) practices. A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha, Hunan Province, China, from 2004 to 2014. Grain yield and yield attributes (panicle number per m², spikelet number per panicle, spikelet filling percentage, grain weight, total biomass, and harvest index) were evaluated as well as the N-use characteristics (total N uptake, internal N-use efficiency, and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage (CT). A significant finding was that there were no significant differences in grain yield, yield attributes, and N-use characteristics between CT and NT. Averaged across the 11 years, grain yield and N requirements were 9.51 t ha^–1 and 20.2 kg t^–1 under CT and 9.33 t ha^–1 and 20.0 kg t^–1 under NT, respectively. There were significant yearly variations in grain yield, yield attributes, and N-use characteristics observed under both CT and NT. The yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle, grain weight, total biomass, and harvest index. Also, it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N requirements. It is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by NT. The results of this study suggest that (1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings, and (2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings.     

Correlation of production constraints with the yield gap of apple cropping systems in Luochuan County,China

Apple occupies a dominant position in fruit production globally, and has become the main income source of local smallholder farmers in Luochuan County in the Loess Plateau area, one of the largest apple production areas in China. However, the annual productivity of apple orchards in this region remains low and has gradually declined over the years. The distinction and correlation of production constraints can contribute to the promotion of apple orchard productivity and the development of a sustainable orchard system. In the present study, survey data from 71 smallholder farmers were analyzed using a yield gap model to distinguish the production constraints and determine their correlation with the yield gap based on the structural equation model(SEM). The results indicated that the average apple yield in Luochuan County was 29.9 t ha~(–1) yr~(–1), while the attainable yield(Y_(att); the highest yield obtained from the on-farm surveys) was 58.1 t ha~(–1) yr~(–1). The average explained and unexplainable yield gaps were 26.3 and 1.87 t ha~(–1) yr~(–1). According to the boundary line analysis, crop load,number of sprayings and base fertilizer N were the top three constraints on apple production in 9.8, 7.8 and 7.8% of the plots, respectively. Among the production constraints, crop load and fruit weight affected apple yield through direct pathways,whereas other constraints influenced apple yield through an indirect pathway based on the SEM, explaining 51% of the yield variance by all the main production constraints. These results can improve the current understanding of production constraints and contribute to the development of management strategies and policies for improving apple yield.     

Yield Evaluation ofTwenty-EightAIfalfa Cultivars in Hebei Province of China

Cultivar selection is important for alfalfa （Medicago sativa L.） hay production. From 2009 to 2012, a field study was conducted to evaluate the dry matter yield （DMY） of 28 cultivars in Cangzhou District of Hebei Province, China, and to determine the most suitable cultivars for this province and other zones with similar climate conditions. 28 alfalfa cultivars were sown in late March of 2009 and were harvested for hay four times in each subsequent year. The results showed that the climatic conditions resulted in significant differences in annual DMY among years, with the second year being the highest and the first year the lowest. The top five cultivars with the highest total DMY were L2750 （62.75 t ha^-1）, Hom （62.72 t ha^-1）, 86-266 （61.55 t ha^-1）, German （61.44 t ha^-1） and Zhongmu 1 （61.18 t ha^-1）, respectively. Across all four years, first harvest had the highest ratios to annual DMY except the cultivar of Rambler, while the fourth harvest had the lowest ratio. There were positive correlation relationships between DMY of each harvest and annual DMY, and the correlation coefficients were all significant in four years. And the path coefficients of first harvest were always the highest in four years. The qualities showed small variations among these cultivars and the cultivar L3750 presented the highest crude protein in both years. Crude protein had significant positive correlation with relative feed value （RFV） in both years while crude fiber had significant negative correlation with RFV and crude fiber.     

Algorithms for sensor-based redistribution of nitrogen fertilizer in winter wheat

Several methods were developed for the redistribution of nitrogen (N) fertilizer within fields with winter wheat (Triticum aestivum L.) based on plant and soil sensors, and topographical information. The methods were based on data from nine field experiments in nine different fields for a 3-year period. Each field was divided into 80 or more subplots fertilized with 60, 120, 180 or 240 kg N ha⁻¹. The relationships between plot yield, N application rate, sensor measurements and the interaction between N application and sensor measurements were investigated. Based on the established relations, several sensor-based methods for within-field redistribution of N were developed. It was shown that plant sensors predicted yield at harvest better than soil sensors and topographical indices. The methods based on plant sensors showed that N fertilizer should be moved from areas with low and high sensor measurements to areas with medium values. The theoretical increase in yield and N uptake, and the reduced variation in grain protein content resulting from the application of the above methods were estimated. However, the estimated increases in crop yield, N-uptake and reduced variation in grain protein content were small.     

Plants diagnostics of nitrogen nutrition of flax

Field experiments with fiber-flax varieties Zaryanka, the Alpha and the Lada was carried out on soddy-podzolic soil under Northern part of the Nonchernozem zone. As a result of 5 years of research studied the influence of increasing doses of nitrogen fertilizer on the dynamics of mineral nitrogen in the soil, total nitrogen content of the flax plant. The mathematical model of flax straw yield has been developed. It was revealed that the increase of productive moisture reserves in the soil from 30 to 40 mm in a layer of 0–40 cm in the phase of “herringbone”–the beginning of rapid growth, increased productivity of flax straw varieties Alpha on 2.8 t ha^–1. The simultaneous increase in the total nitrogen content of the flax plants in the phase of “herringbone” on the 0.1% increment crop yield increase up to 3.0 t ha^–1.     

How plant density affects maize spike differentiation,kernel set,and grain yield formation in Northeast China?

A two-year field experiment was conducted to evaluate the effects of plant density on tassel and ear differentiation, anthesissilking interval(ASI), and grain yield formation of two types of modern maize hybrids(Zhongdan 909(ZD909) as tolerant hybrid to crowding stress, Jidan 209(JD209) and Neidan 4(ND4) as intolerant hybrids to crowding stress) in Northeast China. Plant densities of 4.50×104(D1), 6.75×104(D2), 9.00×104(D3), 11.25×104(D4), and 13.50×104(D5) plants ha~(-1) had no significant effects on initial time of tassel and ear differentiation of maize. Instead, higher plant density delayed the tassel and ear development during floret differentiation and sexual organ formation stage, subsequently resulting in ASI increments at the rate of 1.2–2.9 days on average for ZD909 in 2013–2014, 0.7–4.2 days for JD209 in 2013, and 0.5–3.7 days for ND4 in 2014, respectively, under the treatments of D2, D3, D4, and D5 compared to that under the D1 treatment. Total florets, silking florets, and silking rates of ear showed slightly decrease trends with the plant density increasing, whereas the normal kernels seriously decreased at the rate of 11.0–44.9% on average for ZD909 in 2013–2014, 2.0–32.6% for JD209 in 2013, and 9.7–28.3% for ND4 in 2014 with the plant density increased compared to that under the D1 treatment due to increased florets abortive rates. It was also observed that 100-kernel weight of ZD909 showed less decrease trend compared that of JD209 and ND4 along with the plant densities increase. As a consequence, ZD909 gained its highest grain yield by 13.7 t ha~(-1) on average at the plant density of 9.00×104 plants ha~(-1), whereas JD209 and ND4 reached their highest grain yields by 11.7 and 10.2 t ha~(-1) at the plant density of 6.75×104 plants ha~(-1), respectively. Our experiment demonstrated that hybrids with lower ASI, higher kernel number potential per ear, and relative constant 100-kernel weight(e.g., ZD909) could achieve higher yield under dense planting in high latitude area(e.g., Northeast China).     

Phosphorous Fertilization Influenced Weeds Attributes and Phenological Characteristics of Mungbean Cultivars (<Emphasis Type="Italic">Vigna radiata</Emphasis> L.)

Weeds are abundant in nature having supreme growth characters over the other economic crop. Weeds show aggressive behavior in term of growth, development, reproduction and for water and nutrients uptake through which dominantly spread over the ground and reduced yield of the economic crop. Weeds frequency and density responded positively to phosphorous application and may retard the production potential of the economic crop. Therefore present study was established in a randomized complete block design with three replications at Agriculture Extension Demonstration plot Matta Circle Swat Pakistan, in summer 2014. Five levels of phosphorous (20, 40, 60, 80 and 100 kg ha^–1) with one control in the form of single super phosphate (SSP) and three cultivars of mungbean (SWAT-I, SWAT-II and NM-54) were used during the experiment. Results revealed that weeds density and phenological traits of mungbean varied with P₂O₅ application. A linear increase in weeds density was observed with increase in P2O5 levels. Fewer days to flowering (40 days) were observed in plots received P at the rate of 80 and 100 kg ha^–1 followed by 60, 40, 20 and 0 kg P ha^–1, while more (44 days) were recorded in control plots. In case of varieties late flowering (42 days) was observed in variety SWAT I followed by SWAT-II, while early flowering (41 days) was recorded in cultivar NM-54. Minimum days (48 days) to pods formation was noticed in P₂O₅ at the rate of 80 and 100 kg ha^–1, while more days (52 days) to pod formation were recorded in control plots. In case of varieties NM-54 took less days (49 days) while SWAT-I were statistically at par. Highest plant height (73.9 cm) was recorded with 60 kg P ha^–1 while at par plant height was noted at the rate of 80 and 100 kg P₂O₅ ha^–1. Shorter plant height (57.3 cm) was recorded in control plots. Maximum leaves plant^–1 (23) were noted at the rate of 80 kg ha^–1, while control plots produced minimum number of leaves plant^–1 (16). In case of mungbean varieties SWAT-I produce maximum leaves plant^–1 (21) followed by SWAT-II (20), while NM-54 produced minimum leaves plant^–1 (19). Biological yield (3978 kg ha^–1) was obtained in the plots treated with 80 kg P ha^–1 while the minimum biological yield (2668 kg ha^–1) was recorded in control plots. Among the varieties SWAT-I produced maximum biological yield (3551 kg ha^–1) followed by SWAT-II (3440 kg ha^–1) and NM-54 (3317 kg ha^–1) respectively.     

Effects of nitrogen fertilizer and chemical regulation on spring maize lodging characteristics,grain filling and yield formation under high planting density in Heilongjiang Province,China

Now,lodging is a major constraint factor contributing to yield loss of maize (Zea mays L.) under high planting density.Chemical regulation and nitrogen fertilizer could effectively coordinate the relationship between stem lodging and maize yield,which significantly reduce lodging and improve the grain yield.The purpose of this study was to explore the effects of chemical regulation and different nitrogen application rates on lodging characteristics,grain filling and yield of maize under high density.For this,we established a field study during 2017 and 2018 growing seasons,with three nitrogen levels of N100 (100 kg ha~(–1)),N200 (200 kg ha~(–1)) and N300 (300 kg ha~(–1)) at high planting density (90 000 plants ha~(–1)),and applied plant growth regulator (Yuhuangjin,the mixture of 3% DTA-6 and 27% ethephon) at the 7th leaf.The results showed that chemical control increased the activities of phenylalanine ammonia-lyase (PAL),tyrosine ammonia-lyase (TAL),4-coumarate:Co A ligase (4CL),and cinnamyl alcohol dehydrogenase (CAD),and increased the lignin,cellulose and hemicellulose contents at the bottom of the 3rd internode,which significantly reduced the lodging percentage.The lignin-related enzyme activities,lignin,cellulose and hemicellulose contents decreased with the increase of nitrogen fertilizer,which significantly increased the lodging percentage.The 200 kg ha~(–1) nitrogen application and chemical control increased the number,diameter,angle,volume,and dry weight of brace roots.The 200 kg ha~(–1) nitrogen application and chemical control significantly increased the activities of ADP-glucose pyrophosphorylase (AGPase),soluble starch synthase (SSS) and starch branching enzyme(SBE),which promoted the starch accumulation in grains.Additional,improved the maximum grain filling rate (V_(max)) and mean grain filling rate (V_m),which promoted the grain filling process,significantly increased grain weight and grain number per ear,thus increased the final yield.     

Yield performance and optimal nitrogen and phosphorus application rates in wheat and faba bean intercropping

Yield performance in cereal and legume intercropping is related to nutrient management, however, the yield response of companion crops to nitrogen (N) input is inconclusive and only limited efforts have focused on rationed phosphorous (P) fertilization. In this study, two multi-year field experiments were implemented from 2014–2019 under identical conditions. Two factors in a randomized complete block design were adopted in both experiments. In field experiment 1, the two factors included three planting patterns (mono-cropped wheat (MW), mono-cropped faba bean (MF), and wheat and faba bean intercropping (W//F)) and four N application rates (N0, 0 kg N ha^–1; N1, 90 and 45 kg N ha^–1 for wheat and faba beans, respectively; N2, 180 and 90 kg N ha^–1 for wheat and faba beans, respectively; and N3, 270 and 135 kg N ha^–1 for wheat and faba beans, respectively). In field experiment 2, the two factors included three P application rates (P0, 0 kg P₂O₅ ha^–1; P1, 45 kg P₂O₅ ha^–1; and P2, 90 kg P₂O₅ ha^–1) and the same three planting patterns (MW, MF, and W//F). The yield performances of inter- and mono-cropped wheat and faba beans under different N and P application rates were analyzed and the optimal N and P rates for intercropped wheat (IW) and MW were estimated. The results revealed that intercropping favored wheat yield and was adverse to faba bean yield. Wheat yield increased by 18–26%, but faba bean yield decreased by 5–21% in W//F compared to MW and MF, respectively. The stimulated IW yield drove the yield advantage in W//F with an average land equivalent ratio (LER) of 1.12. N and P fertilization benefited IW yield, but reduced intercropped faba bean (IF) yield. Nevertheless, the partial LER of wheat (pLER_wheat) decreased with increasing N application rates, and the partial LER of faba bean (pLER_{faba bean}) decreased with increasing P application rates. Thus, LER decreased as N input increased and tended to decline as P rates increased. IW maintained a similar yield as MW, even under reduced 40–50% N fertilizer and 30–40% P fertilizer conditions. The estimated optimum N application rates for IW and MW were 150 and 168 kg ha^–1, respectively, and 63 and 62 kg ha^–1 for P₂O₅, respectively. In conclusion, W//F exhibited yield advantages due to stimulated IW yield, but the intercropping yield benefit decreased as N and P inputs increased. Thus, it was concluded that modulated N and P rates could maximize the economic and ecological functions of intercropping. Based on the results, rates of 150 kg Nha^–1 and 60 kg P₂O₅ ha^–1 are recommended for IW production in southwestern China and places with similar conditions.     

Identifying the limiting factors driving the winter wheat yield gap on smallholder farms by agronomic diagnosis in North China Plain

North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear. Therefore, increasing the wheat yield in NCP is essential for the national food security. This study monitored wheat yield, management practices and soil nutrient data in 132 farmers' fields of Xushui County, Baoding City, Hebei Province during 2014–2016. These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components(i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield. Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach. The results showed that the attainable potential yield for winter wheat was 10 514 kg ha~(–1). The yield gaps varied strongly between three yield groups(i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha~(–1), respectively. For the three yield components, only spikes per hectare was significantly different(P0.01) among the three yield groups. For all 132 farmers' fields, correlation between yield and spikes per hectare(r=0.51, P0.01), was significantly positive, while correlations with grain number per spike(r=–0.16) and 1 000-grain weight(r=–0.10) were not significant. The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield. Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate(26.7%), followed by basal N input(22.1%) and seeding rate(14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare. For desired spikes per hectare(6.598×10~6 ha~(–1)),the seeding rate should range from 210–300 kg ha~(–1), seeding date should range from 3th to 8th October, and basal N input should range from 90~(–1)80 kg ha~(–1). Compared to these reasonable ranges of management measures, most of the farmers' practices were not suitable, and both lower and higher levels of management existed. It is concluded that the strategies for optimizing yield components could be achieved by improving wheat seeding quality and optimizing farmers' nutrient management practices in the NCP.     

Effects of Plant Density on Yield and Canopy Micro Environment in Hybrid Cotton

A rational plant population is an important attribute to high yield of cotton, because it can provide a beneficial micro environment within the canopy for plant growth and development as well as yield formation. A 2-yr field experiment was conducted to determine the optimal plant density based on cotton yield in relation to the canopy micro environment （canopy temperature, relative humidity and light transmittance）. Six plant densities （1.2-5.7 plants m^-2） were arranged with a completely randomized block design. The highest cotton yield （1 507 kg ha^-1） was obtained at 3.0 plants m^-2 due to more bolls per unit ground area （79 bolls m2）, while the lowest yield （1 091 kg ha1） was obtained at 1.2 plants m^-2. Under the moderate plant density （3.0 plants m^-2）, there was a lower mean daily temperature （MDT, 27. 1℃） attributing to medium daily minimum temperature （Train, 21.9℃） and the lowest daily maximum temperature （Tmax, 35.8℃）, a moderate mean canopy light transmittance of 0.51, and lower mean daily relative humidity （MRH） of 79.7% from June to October. The results suggest that 3.0 plants m^-2 would be the optimal plant density because it provides a better canopy micro environment.     

A loss function to evaluate agricultural decision-making under uncertainty: a case study of soil spectroscopy

Modern sensor technologies can provide detailed information about soil variation which allows for more precise application of fertiliser to minimise environmental harm imposed by agriculture. However, growers should lose neither income nor yield from associated uncertainties of predicted nutrient concentrations and thus one must acknowledge and account for uncertainties. A framework is presented that accounts for the uncertainty and determines the cost–benefit of data on available phosphorus (P) and potassium (K) in the soil determined from sensors. For four fields, the uncertainty associated with variation in soil P and K predicted from sensors was determined. Using published fertiliser dose–yield response curves for a horticultural crop the effect of estimation errors from sensor data on expected financial losses was quantified. The expected losses from optimal precise application were compared with the losses expected from uniform fertiliser application (equivalent to little or no knowledge on soil variation). The asymmetry of the loss function meant that underestimation of P and K generally led to greater losses than the losses from overestimation. This study shows that substantial financial gains can be obtained from sensor-based precise application of P and K fertiliser, with savings of up to £121 ha^?1 for P and up to £81 ha^?1 for K, with concurrent environmental benefits due to a reduction of 4–17 kg ha^?1 applied P fertiliser when compared with uniform application.