Foliar K application to rainfed wheat in a soil testing high K as an option to improve K use efficiency,grain yield and yield components

Abstract

Granular application of potassium (K) in soils testing high is generally not recommended. However, the effect of foliar K on rainfed wheat (Triticum aestivum L.) under these soil conditions is largely unknown. The objective of this work was to identify the effect of K fertilizer on K use efficiency (KUE), grain yield and yield components of wheat. The data were collected until 2017 in an ongoing trial established in 2007 with eight treatments; two granular K rates (0 and 50?kg K ha^?1); two foliar N rates (0 and 3?kg N ha^?1); and two foliar K rates (0 and 3?kg K ha^?1) in a split-split plot arrangement. Treatments were applied to the same plots each season. Treatment with foliar K resulted in the highest KUE response but the effect size varied according to the accumulated precipitation during the reproductive stage. On average, KUE was enhanced in crop seasons with water constrains (<179?mm) during the growth period but the converse was true as the amount of precipitation increased. In contrast, granular K had no effect on KUE irrespective of precipitation conditions. Application of foliar K increased grain yield as compared to granular K from 2988 to 3089?kg ha^?1. This enhancement was attributed to an increased number of grains per head. Therefore, foliar K application to wheat is suitable in a soil testing high K to enhance KUE and grain yield, overall in crop seasons with water constrains.     

Furrow diking and N management for dryland wheat production in permanent raised beds

The permanent bed planting system for wheat (Triticum aestivum L.) production has recently received additional attention. Studies using hard red spring wheat (cultivar Nahuatl F2000) were conducted at two locations in central Mexico. The studies included the installation of three furrow diking treatments, two granular N timing treatments and three foliar N rates applied at the end of anthesis. The objective was to evaluate the effect of these factors on wheat grain yield, yield components and grain N in a wheat–maize (Zea maize L.) rotation with residues of both crops left as stubble. Results indicated that diking in alternate furrows increased both grain yield and the final number of spikes per m². The split application of N fertilizer enhanced the number of spikes per m² and grain N uptake, but the effect on grain yield was inconsistent. Similarly, grain protein increased with the foliar application of 6 kg N ha^?1, depending upon the maximum temperature within the 10 days following anthesis. The normalized difference vegetative index (NDVI) readings collected at four growth stages were generally higher for the split N application than for the basal N application at planting. Grain N uptake was associated to NDVI readings collected after anthesis.     

Response of maize (Zea mays) to the application of foliar fertilizers in the Sudan and Guinea savanna zone of Nigeria

Soil fertility problems resulting in low maize yields in smallholder farms are common in the West African moist savanna. The effectiveness of commercial foliar fertilizers in improving maize growth and yield was evaluated in three savanna agro‐ecological zones of Nigeria in two steps. In step one, eight commercial foliar fertilizers were assessed in a greenhouse study with two soil types using maize (Zea mays L. cv. 2004 TZE‐Y POPDT STR C4). The treatments included a control and a reference that received the optimum concentrations of nutrients. In step 2, three promising products from the greenhouse study (Turbotop, Agroleaf General, and Agroleaf high‐P) were evaluated under field conditions to validate the efficacy of products to enhance crop growth and yield. The foliar products were applied at the rate of 5 kg ha^?1. The treatments also included three rates of P application (0, 30, and 60 kg P ha^?1) as triple super phosphate (TSP) with or without foliar fertilizers. In the greenhouse study, differences in maize shoot dry matter yield and N and P concentrations, attributable to the spraying of the commercial foliar fertilizers, were observed for both soils. Spraying Turbotop, Agroleaf General, and Agroleaf high‐P gave the highest shoot dry biomass and N and P uptake compared to other products. Under field conditions, foliar spraying of Agroleaf high‐P significantly increased the shoot dry biomass of maize compared with the 0 P treatment in all locations. The grain yield of maize ranged from 1 to 4 t ha^?1 with significant differences across sites. Products with high concentrations of P and N in their formulation improved maize yield suggesting that appropriate management of P and N resources is a prerequisite for a sustainable maize intensification in the savanna agro‐ecologies.     

Nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide and inorganic nitrogen application rates in a derived savanna

Abstract

Field experiments were conducted to investigate nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide (CaC₂) and nitrogen (N) rates in a derived Savanna (2016 and 2017). Maize cultivars {SUWAN-I [open pollinated variety (OPV)] and OBA SUPER II (hybrid)}, rates of N (0, 60 and 90?kg ha^?1) and CaC₂ (0, 30 and 60?kg ha^?1), were arranged in split-split plot respectively, fitted into a randomized complete block design in three replicates. N Partial factor productivity (PFP_N), Agronomic Use Efficiency (both years) and Apparent recovery of N (2017) increased in the order 60?>?90?>?0?kg N ha^?1, except N Internal use efficiency which was in the order 0?>?60?>?90?kg N ha^?1 (2017). Grain yield increased with increasing rates of N in both years. OBA SUPER-II had significantly higher grain yield than SUWAN-I (2017). Similar pattern was observed on number of grains per cob, dry cob weight, PFP_N and plant height (2017). Conversely in 2016, grain, total and shoot N uptakes were significantly higher in SUWAN-I than OBA SUPER-II. Increasing application of CaC₂ increased grain N uptake and number of grains per cob. Number of leaves and stem girth increased in the order of 60?>?0?>?30?kg?CaC₂ ha^?1. Increased grain yield with N rates could be associated with NHI and N use efficiency. These evidences suggested that hybrid maize performed better than OPV in a derived Savanna.     

Influence of boron fertilization on cauliflower productivity,nutrient uptake and soil nutrient status in an acid Alfisol in Northwestern Himalaya

ABSTRACT

Modern agriculture over the years has resulted in depletion of boron (B) from soil which has been emerged as a serious obstacle for sustainable agriculture. We studied the availability of B in soil and cauliflower (Brassica oleracea var. botrytis L.) productivity under different levels of B fertilization. A field experiment was conducted during 2013–2014 and 2014–2015, at experimental farm of Himachal Pradesh Agricultural University, Palampur on silt-clay loam soil (acid Alfisol) under mid hill wet temperate condition. Different levels of B for the study included 0, 0.75, 1.5, 2.5, 5, 10, 20 and 30 kg B ha^?1 along with recommended dose (RD) of NPK and farmyard manure (FYM, 20 t ha^?1). The application of B influenced biological yield significantly up to 5 kg ha^?1. Highest curd yield in 2013–2014 (11.03 t ha^?1) and 2014–2015 (12.93 t ha^?1) was recorded in 1.5 and 0.75 kg ha^?1 B along with NPK + FYM, respectively. At higher rates of boron i.e. 10, 20 and 30 kg ha^?1, due to toxic effects, a reduction in curd yield was recorded in both years. Maximum mean uptake of N, P and K by leaves and curd was recorded with the application of boron at 1.5 kg ha^?1, whereas mean B uptake was highest when boron was applied at 2.5 kg ha^?1. The highest mean value (1.79 mg kg^?1) of soil available boron was recorded with 30 kg B ha^?1. Application of boron at 2.4 kg ha^?1 was worked out as optimum dose for cauliflower.     

Nonexchangeable Potassium Displacement in Relation to Potassium Availability to Rainfed Maize under Nitrogen Fertilization

A study was conducted to evaluate the effect of nitrogen (N) application, through an easily available and cheap source urea, on potassium (K) displacement and its availability in K-deficient maize-growing soils of rainfed subtropics. The greatest amount of K was displaced (11.22 kg ha^?1) by N application at the rate of 80 kg N ha^?1 (treatment T₄). Amount of N fixed to displace K (11.10 kg ha^?1) was also greatest in the same treatment. Displaced K was positively related to nonexchangeable potassium (NEK) release. Nitrogen application through urea at 80 kg ha^?1 helped not only in meeting N requirement of maize crop in these N-deficient soils but can also satisfy the K requirements (as these soils are low in K) of these soils. Potassium displacement also increased the production efficiency of the maize crop by promoting its relative production efficiency index (RPEI) from suitability class V to class III.     

Biomass production and N fixation of five Mucuna pruriens varieties and their effect on maize yields in the forest zone of Cameroon

Mucuna has been tested intensively in past years as green manure for intensive maize production in West Africa. However, information is missing about the yield effect of different existing mucuna varieties. Five Mucuna pruriens varieties were grown for 40 weeks followed by sole maize (Zea mays L.) in order to determine differences in biomass production, nitrogen fixation, and effects on maize yield. Mucuna varieties differed in length of growing period, total biomass production (5.9—8.8 Mg ha^—1), seed production (0.65—1.3 Mg ha^—1), nitrogen (N) uptake (147—222 kg ha^—1), N fixation (87—171 kg ha^—1), and the amount of N retained in residues (138—218 kg ha^—1). The grain yield of maize grown immediately after the short mucuna fallow was significantly higher after mucuna vars. jaspaeda (4.60 Mg ha^—1), utilis (3.49 Mg ha^—1), and cochinchinensis (3.44 Mg ha^—1), compared with a non‐fertilized control (1.93 Mg ha^—1) which had a maize crop and vegetation regrowth before. After mucuna vars. ghana and veracruz, 2.90 and 2.65 Mg ha^—1 of maize grain were produced, respectively. No significant correlation between mucuna biomass and its N uptake and maize grain yield was found, whereas maize stover yield showed a significant positive correlation. Application of 30, 60, and 90 kg ha^—1 N as <?tw=98%>urea on sub‐plots of the control yielded 2.20, 3.19, and 3.46 Mg ha^—1 <?tw>of maize grain in the first year. Only the difference between 0 and 90 kg ha^—1 N was significant. Fertilizer N equivalent values for mucuna varieties ranged from 41 to 148 kg ha^—1. The yield advantage of vars. jaspaeda, utilis, and cochinchinensis versus the control without N fertilizer application was confirmed in the following year, with no significant difference in maize grain yield between mucuna and the control with N fertilizer application.<?show $6#>     

Effect of Nitrogen on Yield and Some Quality Parameters of Sweet Corn

Sweet corn consumption has increased considerably worldwide. Sweet corn is produced for human consumption as either a fresh or a processed product. The nutrient composition of sweet corn is very important for human health and diet. This study aimed to determine the best nitrogen (N) dosage for sweet corn. Kernel mineral composition and protein content were determined for different N rates. The research was carried out during 2003 and 2004 in Sanliurfa, Turkey. Nitrogen application rates were 120, 160, 200, 240, 280, 320, and 360 kg N ha^?1 with control. The fresh ear yield per hectare and the protein and mineral contents of kernel were significant (P < 0.01). The lowest yield was obtained at low N applications, whereas increasing N applications increased the fresh ear yield and protein content of kernel. Nitrogen-use efficiency increased up to 320 kg ha^?1 N dosage (60.2% and 58.6% for 2003 and 2004, respectively), and a decrease was seen at 360 kg ha^?1 N dosage. Leaf area index and root dry matter increased with increasing N supply. The copper concentration of the kernel was generally positively affected by increasing N application. Iron and zinc contents of kernels increased, whereas manganese content decreased, with increasing N doses. At the focus of regression analysis, the best N dosage was 320 kg ha^?1 along with the soil N content for Vega sweet corn variety grown in the southeastern Anatolia region of Turkey.     

Nitrous oxide emissions from a rainfed-cultivated black soil in Northeast China: effect of fertilization and maize crop

Nitrous oxide emission (N₂O) from applied fertilizer across the different agricultural landscapes especially those of rainfed area is extremely variable (both spatially and temporally), thus posing the greatest challenge to researchers, modelers, and policy makers to accurately predict N₂O emissions. Nitrous oxide emissions from a rainfed, maize-planted, black soil (Udic Mollisols) were monitored in the Harbin State Key Agroecological Experimental Station (Harbin, Heilongjiang Province, China). The four treatments were: a bare soil amended with no N (C0) or with 225?kg?N ha^?1 (CN), and maize (Zea mays L.)-planted soils fertilized with no N (P0) or with 225?kg?N ha^?1 (PN). Nitrous oxide emissions significantly (P?<?0.05) increased from 141?±?5?g N₂O-N?ha^?1 (C0) to 570?±?33?g N₂O-N?ha^?1 (CN) in unplanted soil, and from 209?±?29?g N₂O-N?ha^?1 (P0) to 884?±?45?g N₂O-N?ha^?1 (PN) in planted soil. Approximately 75?% of N₂O emissions were from fertilizer N applied and the emission factor (EF) of applied fertilizer N as N₂O in unplanted and planted soils was 0.19 and 0.30?%, respectively. The presence of maize crop significantly (P?<?0.05) increased the N₂O emission by 55?% in the N-fertilized soil but not in the N-unfertilized soil. There was a significant (P?<?0.05) interaction effect of fertilization?×?maize on N₂O emissions. Nitrous oxide fluxes were significantly affected by soil moisture and soil temperature (P?<?0.05), with the temperature sensitivity of 1.73–2.24, which together explained 62–76?% of seasonal variation in N₂O fluxes. Our results demonstrated that N₂O emissions from rainfed arable black soils in Northeast China primarily depended on the application of fertilizer N; however, the EF of fertilizer N as N₂O was low, probably due to low precipitation and soil moisture.     

Long continued applications of N fertilizer to cereals on sandy loam: grain and straw response to residual N

Abstract. The residual value of mineral N fertilizer applied in the spring was investigated in a field experiment where four cereals (winter wheat, winter barley, spring barley and spring oats) had been grown at reduced (0.7N), normal (1N) or high (1.3N) N fertilizer rates for 20 to 28 years. The effect of previous N fertilizer dressing was tested in two succeeding years by replacing the original N rate with five test N rates ranging from 0 to 240 kg N ha^?1 for winter cereals and 0 to 200 kg N ha^?1 for spring cereals. In the first test year, winter wheat grown on plots previously supplied with the high rate of mineral fertilizer (202 kg N ha^?1 yr^?1) yielded more grain and straw and had a higher total N uptake than wheat on plots previously supplied with the normal (174 kg N ha^?1 yr^?1) or reduced (124 kg N ha^?1 yr^?1) rate. The grain yield response and N uptake was not significantly affected by the N supply in the test year. The winter wheat grown in the second test year was unaffected by the previous N supply. Grain and straw yield response and total N uptake for spring barley, winter barley and oats, were almost identical irrespective of the previous N rate. After 20 to 28 years there were no significant differences in soil C and N (0 to 20 cm) between soil receiving three rates of N fertilizer. Soil from differently fertilized oat plots showed no significant differences in N mineralizing capacity. Nitrate leaching losses from the soils at the three N rates were estimated and the N balances for the 20 to 28 years experimental period calculated. The data indicated a reduction in overall loss of 189 to 466 kg N ha^?1 at the normal and high N rates compared with the reduced N rate. We conclude that the N supplying capacity and soil organic matter content of this fertile sandy loam soil under continuous cereal cropping with straw removal was not significantly affected by differences in N fertilizer residues.     

Improving organic C and N fractions in a sulfur-deficient soil with S fertilization

A field experiment was conducted over 9?years (1999 to 2007 growing seasons) in northeastern Saskatchewan on a S-deficient Gray Luvisol (Typic Haplocryalf) soil. The objective was to determine the relative effectiveness of N alone versus combined annual application of N (120?kg N?ha^?1) and S (15?kg S?ha^?1) fertilizers to a wheat–canola rotation on storage of total organic C (TOC) and N (TON) and on the light fraction organic C (LFOC) and N (LFON) in soil. Compared to N alone, annual applications of S fertilizer in spring in a combination with N resulted in an increase in soil of TOC (by 2.18?Mg C?ha^?1), TON (by 0.138?Mg N?ha^?1), LFOC (by 1,018?kg C?ha^?1), and LFON (by 42?kg N?ha^?1). The relative increases in organic C or N due to S fertilizer application were much higher for the light organic fractions (36.9% for LFOC and 27.5% for LFON) than for the total organic fractions (9.2% for TOC and 7.3% for TON). The findings demonstrate the importance of a balanced/combined application of N and S fertilizers to crops in storing more organic C and N in this S-deficient soil.     

Possibilities of using sewage sludge as nitrogen fertilizer for maize

Abstract

The objective of this study was to determine the effects of nitrogen fertilizer sources of ammonium sulphate and municipal sewage sludge on yield, N content and uptake of the maize (Zea mays L.). Nutrient and heavy metals were determined in soil and plant. The experiment with three sludge rates (256, 513 and 1026 kg total N ha^?1 or 9.5, 18.0 and 38.1 t ha^?1 sludge), two nitrogen rates (80 and 160 kg N ha^?1) and zero-N control were conducted on a clay loam soils under irrigated conditions in Eastern Anatolia region in Turkey. Treatments were arranged in a randomized complete block design with four replications. Yield, N content and total N uptake of maize increased significantly with sludge application. 9.5 t and 19.0 t ha^?1 sewage sludge applications did not significantly affect heavy metal content of leaf and grain. However, 38.1 t ha^?1 sludge applications increased leaf Pb and Zn. DTPA-extractable Cd, Cu, Fe, Pb and Zn concentrations of the soil increased at applications of 38.1 t ha^?1 sewage sludge, whereas applications of 9.5 t and 19.0 t ha^?1 sludge only resulted in elevated levels of Cu and Zn, We conclude that if sewage sludge is to be used in production of maize, applications rate up to 19 t ha^?1 could be accepted. However, this means also that the N requirement of maize crop is not covered by the sludge; therefore, the rest of nitrogen could be supplied as inorganic N.     

Eucalyptus biochar application enhances Ca uptake of upland rice,soil available P,exchangeable K,yield, and N use efficiency of sugarcane in a crop rotation system

It was hypothesized that the application of eucalyptus biochar enhances nutrient use efficiencies of simultaneously supplied fertilizer, as well as provides additional nutrients (i.e., Ca, P, and K), to support crop performance and residual effects on subsequent crops in a degraded sandy soil. To test this hypothesis, we conducted an on‐farm field experiment in the Khon Kaen province of Northeastern Thailand to assess the effects of different application rates of eucalyptus biochar in combination with mineral fertilizers to upland rice and a succeeding crop of sugarcane on a sandy soil. The field experiment consisted of three treatments: (1) no biochar; (2) 3.1 Mg ha^?1 biochar (10.4 kg N ha^?1, 3.1 kg P ha^?1, 11.0 kg K ha^?1, and 17.7 kg Ca ha^?1); (3) 6.2 Mg ha^?1 biochar (20.8 kg N ha^?1, 6.2 kg P ha^?1, 22.0 kg K ha^?1, and 35.4 kg Ca ha^?1). All treatments received the same recommended fertilizer rate (32 kg N ha^?1, 14 kg P ha^?1, and 16 kg K ha^?1 for upland rice; 119 kg N ha^?1, 21 kg P ha^?1, and 39 kg K ha^?1 for sugarcane). At crop harvests, yield and nutrient contents and nitrogen (N) use efficiency were determined, and soil chemical properties and pH₀ monitored. The eucalyptus biochar material increased soil Ca availability (117 ± 28 and 116 ± 7 mg kg^?1 with 3.1 and 6.2 Mg ha^?1 biochar application, respectively) compared to 71 ± 13 mg kg^?1 without biochar application, thus promoting Ca uptake and total plant biomass in upland rice. Moreover, the higher rate of eucalyptus biochar improved CEC, organic matter, available P, and exchangeable K at succeeding sugarcane harvest. Additionally, 6.2 Mg ha^?1 biochar significantly increased sugarcane yield (41%) and N uptake (70%), thus enhancing N use efficiency (118%) by higher P (96%) and K (128%) uptake, although the sugar content was not increased. Hence, the application rate of 6.2 Mg ha^?1 eucalyptus biochar could become a potential practice to enhance not only the nutrient status of crops and soils, but also crop productivity within an upland rice–sugarcane rotation system established on tropical low fertility sandy soils.     

Zinc and amino acids on wheat-soybean intercropping under no-till management

Abstract

Foliar fertilization with micronutrients and amino acids (AAs) has been used to increase the grain yield and quality of different crops. The aim of the present study was to evaluate the effects of Zn and AAs foliar application on physiological parameters, nutritional status, yield components and grain yield of wheat-soybean intercropping under a no-till management. We used a randomized block experimental design consisting of eight treatments and four replicates. The treatments were five Zn rates (0, 1, 2, 4 and 8?kg ha^?1) and 2?L ha^?1 of AAs and three additional treatments: a control (without the Zn or AA application), 2?kg ha^?1 Zn and 2?kg ha^?1 Zn + 1?L AA. The treatments were applied by spraying during the final elongation stage and at the beginning of pre-earing for the wheat and in growth stage V6 for the soybean for two crop years in a Typic Oxisol (860?g kg^?1 clay). Zinc foliar fertilization increased the wheat grain Zn concentrations. The Zn rates and AA foliar fertilization in soil with did not affect the physiological parameters, nutrient status or yield components. The AA application at the different concentrations tested changed the soybean grain yield and the leaf N concentration. The results suggest that Zn and amino acids application increases the grains Zn concentration in the wheat, being an important strategy to agronomic biofortification.     

Field-level comparison of nitrogen rates and application methods on maize yield,grain quality and nitrogen use efficiency in a humid environment

Appropriate nitrogen (N) management practices are of critical importance in improving N use efficiency (NUE), maize (Zea mays) yield and environmental quality. A six-year (2005–2010) on-farm trial was conducted in Ottawa, Canada to assess the effects of N rates and application methods on grain yield and NUE. In four out of the six-year study, grain yield increased by 60–77 kg ha^?1 by sidedress, compared to 49–66 kg ha^?1 for each kg N ha^?1 applied at preplant. Grain yield response to N between the two strategies was similar in the other growing seasons. Sidedress strategy required 15 kg N ha^?1 less of the maximum economic rate of N (MERN) than preplant application. Our results indicate that sidedress application of 90–120 kg N ha^?1 with a starter of 30 kg N ha^?1 resulted in greater yield, grain quality and NUE than preplant N application in this cool, humid and short growing-season region.     

Influence of Soil and Fertilizer Nutrients on Sustainability of Rainfed Finger Millet Yield and Soil Fertility in Semi-arid Alfisols

Productivity of rainfed finger millet in semiarid tropical Alfisols is predominantly constrained by erratic rainfall, limited soil moisture, low soil fertility, and less fertilizer use by the poor farmers. In order to identify the efficient nutrient use treatment for ensuring higher yield, higher sustainability, and improved soil fertility, long term field experiments were conducted during 1984 to 2008 in a permanent site under rainfed semi-arid tropical Alfisol at Bangalore in Southern India. The experiment had two blocks—Farm Yard Manure (FYM) and Maize Residue (MR) with 5 fertilizer treatments, namely: control, FYM at 10 t ha^?1, FYM at 10 t ha^?1 + 50% NPK [nitrogen (N), phosphorus (P), potassium (K)], FYM at 10 t ha^?1 + 100% NPK (50 kg N + 50 kg P + 25 kg K ha^?1) and 100% NPK in FYM block; and control, MR at 5 t ha^?1, MR at 5 t ha^?1 + 50% NPK, MR at 5 t ha^?1 + 100% NPK and 100% NPK in MR block. The treatments differed significantly from each other at p < 0.01 level of probability in influencing finger millet grain yield, soil N, P, and K in different years. Application of FYM at 10 t ha^?1 + 100% NPK gave a significantly higher yield ranging from 1821 to 4552 kg ha^?1 with a mean of 3167 kg ha^?1 and variation of 22.7%, while application of maize residue at 5 t ha^?1 + 100% NPK gave a yield of 593 to 4591 kg ha^?1 with a mean of 2518 kg ha^?1 and variation of 39.3% over years. In FYM block, FYM at 10 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.45%), available N (204 kg ha^?1), available P (68.6 kg ha^?1), and available K (107 kg ha^?1) over years. In maize residue block, application of MR at 5 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.39%), available soil N (190 kg ha^?1), available soil P (47.5 kg ha^?1), and available soil K (86 kg ha^?1). The regression model (1) of yield as a function of seasonal rainfall, organic carbon, and soil P and K nutrients gave a predictability in the range of 0.19 under FYM at 10 t ha^?1 to 0.51 under 100% NPK in FYM block compared to 0.30 under 100% NPK to 0.67 under MR at 5 t ha^?1 application in MR block. The regression model (2) of yield as a function of seasonal rainfall, soil N, P, and K nutrients gave a predictability in the range of 0.11 under FYM at 10 t ha^?1 to 0.52 under 100% NPK in FYM block compared to 0.18 under MR at 5 t ha^?1 + 50% NPK to 0.60 under MR at 5 t ha^?1 application in MR block. An assessment of yield sustainability under different crop seasonal rainfall situations indicated that FYM at 10 t ha^?1 + 100% NPK was efficient in FYM block with a maximum Sustainability Yield Index (SYI) of 41.4% in <500 mm, 64.7% in 500–750 mm, 60.2% in 750–1000 mm and 60.4% in 1000–1250 mm rainfall, while MR at 5 t ha^?1 + 100% NPK was efficient with SYI of 29.6% in <500 mm, 50.2% in 500–750 mm, 40.6% in 750–1000 mm, and 39.7% in 1000–1250 mm rainfall in semi-arid Alfisols. Thus, the results obtained from these long term studies incurring huge expenditure provide very good conjunctive nutrient use options with good conformity for different rainfall situations of rainfed semiarid tropical Alfisol soils for ensuring higher finger millet yield, maintaining higher SYI, and maintaining improved soil fertility.     

Yield and yield components of white bean (Phaseolus vulgaris L.) cultivars affected by boric acid rates and methods of application

To investigate the effect of boric acid on yield and yield components of three white bean cultivars consisted of Jules, G11867, and Shekoofa, a 2-year field split-plot experiment was carried out based on a randomized complete block design with three replications during 2013 and 2014. Boron treatments consisted of 1 – control (no boric acid), 2 and 3 – application of 2 and 4?kg ha^?1 of boric acid by irrigation water, respectively, 4 and 5 – foliar spray of 0.025% and 0.05% of boric acid solutions, respectively, and 6 – combination of 2?kg ha^?1 of boric acid in irrigation water?+?foliar spray by 0.025% boric acid solution. Boron application significantly increased yield and its components in respect to control. The highest grain yields of all cultivars were obtained from application of 2?kg ha^?1 boric acid mixed in irrigation water?+?foliar spray by 0.025% of boric acid solution.     

Effect of nitrogen rates applying controlled-release and conventional urea blend in maize

Abstract

Blending polymer-sulfur coated urea (PSCU) and conventional urea (U) for maize (Zea mays L.) fertilization can supply nitrogen (N) during the crop cycle with a single application. Proper placement of PSCU?+?U (0.15?m below and 0.1?m to the side of seed row) in band application at sowing is necessary to reduce salt stress that can decrease dry weight (DU) and N uptake (NU) of maize plant compromising maize yield. It is not clear the proper N rate in the proper placement for band application of PSCU?+?U at maize sowing to avoid salt stress. In the current literature, reduction of N rates are being recommended using PSCU?+?U without consider the probably salt stress provided by high rates of PSCU?+?U. DW and NU in maize plant as well as soil pH and electrical conductivity (EC) were evaluated in a greenhouse pot trial. N treatments were equivalent to 0, 90, 180, 360 and 540?kg N ha^?1 applied incorporated in band in two contrasting soils (Rhodic Eutrustox and Typic Haplustox) using 70%PSCU + 30%U. At V10 (vegetative leaf stage 10), DW and NU of maize aerial part had quadratic behavior in response to increase N rates in the Typic Haplustox soil. In the Rhodic Eutrustox was not observed known behavior for DW and NU in response to increase N rates. Soil pH and EC was higher in the fertilizer row than sowing row. A N rate above of 180?kg N ha^?1 using 70%PSCU + 30%U incorporated in bands can reduce DW and NU in early maize plant growth associated with salt concentration of N fertilizer in a Typic Haplustox soil, which could compromise maize yield.     

Liming and Nitrogen Effects on Maize Yield and Nitrogen Use Efficiency

ABSTRACT

The study was aimed to determine the appropriate nitrogen (N) rate to combine with liming for enhanced maize yield and nitrogen use efficiency (NUE). Two maize varieties [Ikom White (IKW) and Obatanpa-98 (Oba-98)], two lime rates (0 kg ha^?1 and 500 kg ha^?1) and three N rates (0, 90 and 180 kg ha^?1) were used. The treatments were laid as a split-split plot in a randomized complete block design with three replications. The growth attributes, photosynthetically active radiation (PAR), harvest index, dry matter, and grain yield increased (P ≤ 0.05) with increases in N rates, especially in plots amended with lime. Oba-98 was better yielding (2.12 versus (vs) 1.88 t ha^?1) and absorbed more (P ≤ 0.05) radiation (442.06 vs 409.54 μmol m^?2s^?1) than IKW. The efficiency indices and partial factor productivity were best optimized at the 90 kg ha^?1 N rate with Oba-98 having higher values than IKW. Therefore, liming (500 kg ha^?1) plus N at 180 kg ha^?1produced the best yield of the hybrid maize, Oba-98.     

Effects of Conjunctive Nutrient Management on Soil Fertility and Overall Soil Quality Index in Submountainous Inceptisol Soils under Rainfed Maize (Zea mays L.)–Wheat (Triticum aestivum) System

The present long-term study was initiated to quantify the long-term effects of conjunctive nutrient management on soil quality, identify key indicators, and assess soil quality indices under a rainfed maize–wheat system in marginal Inceptisol soils in India. Results of the study revealed that soil organic carbon was significantly influenced by the conjunctive nutrient-management treatments. Among the nine treatments, the application of 100% recommended dose of nitrogen (RDN) (80 kg N ha^?1), 15 kg N (compost) + 20 kg N ha^?1 (inorganic), 25 kg N (compost), and 15 kg N (compost) + 10 kg N ha^?1 (green leaf) resulted in greater organic carbon contents of 5.57, 5.32, 5.27, and 5.26 g kg^?1, which were greater by 29.5%, 24%, 23%, and 22%, respectively, over the control. The greatest soil quality index (1.61) was observed with application of 25 kg nitrogen (N; compost) as well as with application of 15 kg N (compost) + 10 kg N ha^?1 (green leaf). The order of percentage contribution of key indicators toward soil quality indices was available potassium (K) (34%) > available phosphorus (P) (32%) > available N (13%) > microbial biomass carbon (12%) > exchangeable calcium (Ca) (9%). The linear regression equation revealed the principal role of soil quality indicators in maize crop yield. The methodology and the results of the study could be of great relevance in improving and assessing soil quality not only for the study locations but also for other climatically and edaphically identical regions across the world.