Pea-oat intercrops are superior to pea-wheat and pea-barley intercrops

Abstract

A three-year field experiment was conducted in Estonia to determine which combinations of pea (Pisum sativum L.) and wheat (Triticum aestivum L.), oats (Avena sativa L.) and barley (Hordeum distichon L.) were most suitable for mixed cultivation and the effect of pea on the yield potential of cereals. The inclusion of pea in cereal seeds and the increasing of its seed density led to substantial decreases in the grain yields of the cereal component. The reason for these decreases was the formation of smaller grains in cereals when intercropped with pea. The inclusion of pea in a cereal crop and the increasing of its seed density led to substantial increases in the protein content of the cereal grains. In barley and oats the increases in grain protein content were the lowest of the three cereals. At the same time, the maximum protein yield per area unit in cereals was obtained from plots of pure crops. In a mix with pea, the amounts of nitrogen consumed by cereals decreased and the protein yield of cereals per area unit were reduced in intercrops. Pea-cereal mixes had an advantage over cereal sole crops with regard to protein yield, due to the pea component. Pea-cereal mixes are particularly suitable for the conditions of organic farming, and should be recommended to farmers, as they ensure a relatively good harvest and high protein yield on soil without nitrogen fertilizers. In conclusion, the study showed that, of the three combinations, pea-oat mixed intercrops gave the highest yield of grain and protein yields.     

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.     

Economic and environmental optimization of nitrogen fertilizer recommendations for cereals in Norway

Abstract

Results of 240 annual N fertilizer trials in 1991–2007 in spring and winter cereals are presented. On average, spring barley and oat yields increased little beyond 120 kg N ha^?1 in fertilizer. Somewhat higher figures were found for spring and winter wheat. Regression equations for yield and N uptakes in grain and straw were derived, related to N fertilizer input and the yield level in individual trials (indicator of yield expectancy). These equations accounted for 90% of the variation in yield and 80% of that in N uptake. Quadratic N responses were significant in all cases, as were interactions between N responses and yield level. They were verified with data from 27 separate trials performed in 2008–2010. The yield equations were used to calculate economically optimum N fertilizer levels with varying ratios of product price to fertilizer cost at contrasting levels of yield. The optimum N fertilizer level for barley and oats was found to increase by 8.3 kg N ha^?1 per Mg increase in expected yield. The equivalent figure in wheat was 16.3 kg N ha^?1. Optimum N fertilizer levels decreased by 4.1 and 6.7 kg N ha^?1, for barley/oats and wheat respectively, per unit increase in the cost/price ratio. The equations for N uptake were used to calculate simple N balances between fertilizer input and removal in crop products. Large N surpluses were indicated at low levels of yield expectancy, but the surplus declined markedly with increasing yield level, despite greater N fertilizer inputs at high yield. Calculations made for national average yield levels in recent years showed N surpluses of 50–60 kg N ha^?1 when only grain is removed and 25–40 kg N ha^?1 when straw is removed also. Limiting N input to obtain zero balance reduces yields considerably at average levels of yield expectancy.     

Do farmers in Germany exploit the potential yield and nitrogen benefits from preceding oilseed rape in winter wheat cultivation?

Field experiments show that wheat grown after oilseed rape (OSR) achieves higher yield levels, while the nitrogen (N) application is reduced. However, field experiment data are based on few locations with optimised management. We analysed a large dataset based on farm data to assess the true extent of break crop benefits (BCB) for yield and N fertilisation within German commercial farming.

Across all German states and years, average yield of wheat preceded by OSR was 0.56 Mg ha^?1 higher than yield of wheat preceded by cereals (7.09 Mg ha^?1), although considerable variation between regions was observed. Mean N application across all states to wheat after OSR was 5 kg ha^?1 lower than to wheat after cereals. Choice of wheat types for different end uses (bread flour or animal feed) showed higher (0.77 Mg ha^?1) or lower (0.44 Mg ha^?1) BCB for yield of wheat cultivated after OSR compared with after cereals. The calculated BCB for yield and N fertilisation were lower than expected from dedicated field experiments and fertiliser recommendations. Thus the advantages of OSR as a preceding crop are generally utilised by commercial farmers in Germany but there is room for improvement.     

Yield formation of five crop species under water shortage and differential potassium supply

A long‐term field experiment on a Haplic Phaeozem, established 1949 with four levels of potassium (K) supply (5, 69, 133, and 261 kg K ha^?1), was analyzed for the interaction between K supply and yield loss of five crop species by water shortage. The crop species were cultivated simultaneously side‐by‐side in the following rotation: potato (Solanum tuberosum L.), silage maize (Zea mays L.), spring wheat (Triticum aestivum L.), beet (Beta vulgaris L.), and spring barley (Hordeum vulgare L.). The treatment with 133 kg K ha^?1 supply had a nearly balanced K budget. In the treatments with lower supply, the soil delivered K from its mineral constituents. On the low‐K plots (especially on those with only 5 kg K ha^?1), crops suffered yield depressions of nearly all main harvest products (cereal grains, potato tubers, beet storage roots, silage maize) and by‐products (straw, beet leaves) by up to 40.7% of dry matter. Only wheat grains were an exception. Potassium concentrations in the harvested plant parts decreased nearly in parallel to the reduction of their dry matter yields, with the exception of cereal grains, which kept stable concentrations even in the treatment with only 5 kg K ha^?1. A comparison of four year‐pairs with differing levels of precipitation in yield‐relevant periods showed an average water shortage‐induced depression of dry matter yields by 19.7% in the main harvest products. The severity of this yield depression was not mitigated by elevated K supply, with the exception of beet leaves, where the dry matter production was stabilized by high K supply. In this crop, the reduction of storage‐root yield was associated with a decrease in harvest index and was therefore obviously caused by an inhibition of assimilate translocation from the leaves into these organs, in contrast to cereals, where water shortage primarily affected dry matter production in vegetative organs. It is concluded that the physiological causes of yield reduction by drought stress and the possibility of its amelioration by K supply differ between plant species and organs.     

Residual nitrogen effects on a succeeding oat (Avena sativa L.) Crop of clover species and ryegrass (Lolium perenne L.) undersown in winter wheat (Triticum aestivum L.)

The aim of the present investigation was to study the effect of white clover (var. Milka and Donna), red clover (var. Fanny) and ryegrass (var. Tove) undersown in winter wheat on a succeeding oat crop. Under the climatic conditions prevailing in Sweden, growing a catch crop after winter cereals is of particular interest because the latter are usually followed by a spring sown crop, leaving the ground bare during autumn and winter. Field trials were carried out during three growing seasons in an integrated farming system and for one year in an organic farming system. Competition from the dense wheat crop in the integrated farming system had a negative effect on the undersown species, and at harvest of the wheat they showed quite poor growth in all three years, with nitrogen contents under 5 kg ha^?1. No significant yield increase was measured without added nitrogen when the averages for all three years were calculated. On average, the grain yields were improved by 750 kg ha^?1 (14% moisture content) for the treatments with undersown clover for all three years when 90 kg N ha^?1 were added. The experiment within the organic system showed a different pattern with a better development of the undersown clover species, with nitrogen contents approximately 25 kg ha^?1 and an improvement in oat grain yield, from around 2?000 kg ha^?1 for the control to almost 3?500 kg ha^?1 with clover undersown the previous year.     

Yield and yield components of two irrigated red bean cultivars and some soil properties as influenced by wheat residues and nitrogen management

Crop residues are beneficial substances affecting crop production and soil properties. A field experiment was carried out to evaluate the effects of wheat (Triticum aestivum L.) residue rates (0, 25, 50 and 75%) combined with N levels (0, 34.5, 69, 103.5 kg ha^?1) on yield and yield components of two red common bean (Phaseolus vulgaris L.) cultivars and to monitor chemical soil parameters. The experiment was conducted at Research Center, College of Agriculture, Shiraz University, Shiraz, Iran for two years (2008–2009). The experiment was conducted as a split–split plot arranged in a randomized complete blocks design with three replications. The highest seed yield was obtained when 25–50% of residues were incorporated. The highest seed yield, seed weight per plant, 100-seed weight and seed number per pod were obtained with 103.5 kg N ha^?1 with no significant difference to 69 kg N ha^?1. Residue incorporation significantly increased soil organic carbon (SOC) as well as available K and P content. It is possible to sow red common bean as a double cropping by soil incorporation of 25–50% wheat residues with application of 69 kg N ha^?1.     

Manganese foliar supplementation impacts rice yield in tropical lowlands

Abstract

The aim of this work was to evaluate manganese (Mn) sources and levels effects in irrigated rice production in central Brasil (tropical lowlands of Tocantins state). The experiment was conducted in a 5x5?+?1 factorial scheme, five Mn sources and five levels (0.5; 1.0; 1.5; 2.0; and 2.5?kg ha^?1), applied in induction of tillering of rice plants, plus a control without treatment, and Mn content in leaves (mg kg^?1), number of panicles per area (m²), hundred grains weight (g), intact grains (%), and grain yield (kg ha^?1) were analyzed. Treatments with Mn-carbonate source got the best results and this source at the level of 1.5?kg ha^?1 provided the highest yield: 7,375?kg ha^?1. Higher values were obtained with the application of 1.0 to 1.5?kg ha^?1 of Mn, except for the intact grains where the best means were obtained at 2.5?kg ha^?1.     

The effects of pure and undersowing green manures on yields of succeeding spring cereals

Abstract

A field experiment was conducted in 2004–2006 to investigate the effect of green manure treatments on the yield of oats and spring barley. In the experiment, different green manure crops with undersowing and pure sowing were compared for amounts of N, C, and organic matter driven into soil and their effect on cereal yield. The spring barley field had a total of 41.7–62.4 kg N ha^?1 and 1.75–2.81 Mg C ha^?1 added to the soil with straw, weed, and roots, depending on the level of fertilisation; with red clover, and both common and hybrid lucerne undersowing, with barley straw and roots, the values were 3.45–3.96 Mg C ha^?1 and 139.9–184.9 kg N ha^?1. Pure sowings of these three leguminous green manure crops had total applications of 3.37–4.14 Mg C ha^?1 and 219.7–236.8 kg N ha^?1. The mixed and pure sowing of bird's-foot trefoil provided considerably less nitrogen and carbon to the soil with the biomass than with the other leguminous crops. Application of biomass with a high C/N ratio reduced the yield of the succeeding spring cereals. Of the green manures, the most effective were red clover and both common and hybrid lucerne, either as undersowing or as pure sowing. Undersowings with barley significantly increased the N supply for the succeeding crop without yield loss of the main crop compared with the unfertilised variant. Compared with ploughing-in of green manure in autumn, spring ploughing gave a 0.2–0.57 Mg ha^?1 larger grain yield.     

The effect of organic and chemical fertilizers on oilseed rape productivity and weed competition in short rotation

Abstract

A two-year field experiment was conducted to investigate the impact of short crop rotation and organic amendments on rapeseed yield under weed competition conditions. The primary experimental plots consisted of either triticale or pea as a prior crop, consisting of four subplots with either 25 tons of composted cattle manure (CCM), 150?kg urea N ha^?1 (N), 25 tons composted cattle manure + 75?kg urea N ha^?1 (CCM?+?N), or no urea N or manure added as the control (C0). Rapeseed seed yield was not significantly affected by previous crops, except for rapeseed grown after pea which had slightly higher seed yield (2058?kg ha^?1) than those grown after triticale (1942?kg ha^?1). Plants that received CCM?+?N produced the highest amount of seed yield (2447?kg ha^?1), but were not significantly different from plants that received just urea N (2218?kg ha^?1). Weeds gained more biomass when the previous crop was pea compared to those whose previous crop was triticale. Weeds in plots that received CCM?+?N produced the greatest biomass, followed by N, and CCM plots, respectively.     

Optimizing seed crops of common bent (Agrostis capillaris) by sowing rate

Abstract

As part of a project to stimulate Norwegian seed production of common bent (syn. browntop, US: colonial bentgrass, Agrostis capillaris L. syn. A.tenuis Sibth.) field trials comparing sowing rates of 2.5, 5.0, 7.5 or 10 kg ha^?1 were conducted at Landvik, south-east Norway, (58°N) from 1989 to 1994. Three trials were laid out of the forage cultivar ‘Leikvin’ and three trials of the lawn cultivar ‘Nor’, each trial being harvested for three consecutive years. While the average per cent ground cover in spring increased from 87% at 2.5 kg ha^?1 to 94–96% at 7.5 kg ha^?1, seed yields decreased with increasing sowing rate in both cultivars. On average for all harvests, quadrupling the sowing rate from 2.5 to 10 kg ha^?1 reduced seed yield by 9% in ‘Leikvin’ and 15% in ‘Nor’, the stronger effect probably being associated with a greater competition between tillers in the lawn cultivar. Seed yield reductions with increasing sowing rate showed no relationship with crop age, but were less accentuated for crops undersown in spring wheat in a dry year than for crops established without cover crop in years with ample rainfall in early summer. Increasing sowing rates reduced plant height and panicle number in ‘Nor’, but had no effect on seed weight or germination in any of the cultivars. It is concluded that seed crops of common bent should be established with a sowing rate of 2–5 kg ha^?1, with the lowest rate in lawn cultivars, under ideal seedbed conditions and when seed crops are sown without cover crop.     

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.     

Optimizing the NPK application in white mustard (Sinapis alba L.) under an arid climate in Punjab,Pakistan

The production of oil from the conventional oilseed seed crops (viz. mustard, rapeseed) is not sufficient to meet the demands of Pakistani people. Due to this reason, a surplus quantity of oil is imported every year from different countries to fulfill the domestic demands of the cooking oil. This 2-year study was aimed to optimize the dose of NPK for profitable production of white mustard. Nitrogen (0, 60, 90?kg ha^?1), phosphorous (0, 30, 60?kg ha^?1) and potassium (0, 75, 100?kg ha^?1) were applied in various combinations. The results indicated that highest seed yield and profitability was recorded with NPK at 90–60–100?kg ha^?1, which was attributed to improvement in crop growth. In crux, application of NPK at pre-optimized rate might be a viable option to improve the growth, yield, oil quality, and economics of white mustard production under arid climates in Pakistan. According to the results, a balanced use of NPK fertilization is a key management strategy for white mustard growing farmers of arid region.     

Residual Effect of Copper and Zinc from Fertilizers on Plant Concentration,Phytotoxicity, and Crop Yield Response

Abstract

To avoid toxicity resulting in reduced crop yields and/or phytotoxic symptoms on the foliage, information on the residual effect of micronutrient fertilization after periods of application is desirable. This article includes discussion on the micronutrients copper (Cu) and zinc (Zn), because they are essential and are of concern from plant and animal standpoints. In general, no detrimental effects in yield reduction or phytotoxicity were noted from Cu applications of up to 50 kg Cu ha^?1 to barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.). Barley was an exception where 50 kg Cu ha^?1 decreased yield by about 12% in the first‐year crop. The Cu levels in plants did not exceed 9 mg kg^?1. Studies showed that Zn applications of 50 kg ha^?1 for 2 years in succession and the resulting crop tissue Zn levels as high as 105 mg kg^?1 did not cause any phytotoxicity in cereals. The results of this study suggest that cereals can tolerate high levels of Cu and Zn.     

“Egusi” melon seed yield,proximate content and soil nutrient changes with poultry manure fertilization

Abstract

“Egusi” melon (Colocynthis citrullus L.) is a seed vegetable whose yield is limited by nutrient supply. Two field experiments were conducted with “Egusi” melon at the Crops Research Farm of the Federal University of Agriculture, Abeokuta, Nigeria, to evaluate response of poultry manure (PM) rate on seed yield, seed proximate content, and changes in soil nutrients. The study was conducted from May to August 2013 and repeated same period in 2014 using PM at: 0, 2, 4, 6, 8, and 10 t ha^?1. With the first planting, seed yields of 458 and 452?kg?ha^?1 from applications of 6 and 8 t ha^?1 PM were similar with the highest of 522?kg?ha^?1 from application of 10 t ha^?1 PM. The second planting, with residual fertilizer effect had a higher seed yield of 242?kg?ha^?1 from application of 10 t ha^?1 PM. Number of seeds per fruit was higher; 183 seeds per fruit in the first planting and 163 seeds per fruit in the second planting, from plants treated with 10 t ha^?1 PM. Shelling percent was comparable in both experiments. It was 19.5% with application of 10 t ha^?1 PM and 33.4% with the unfertilized plants for the first planting but was 28.0% with application of 10 t ha^?1 PM and 31.3% with the unfertilized plants for the second planting. Seed crude protein, crude fiber and ash contents were enhanced with application of 10 t ha^?1 PM. Soil pH in the first planting was reduced from initial 6.8 to 6.6 with the unfertilized plants and to 6.7 with applications of 2 and 10 t ha^?1 PM, but increased to 7.1 with application of 6 t ha^?1 PM. In the second planting, it was reduced to 5.0 with applications of 0, 2 and 4 t ha^?1 PM but to 5.3, 5.1, and 5.2 with applications of 6, 8, and 10 t ha^?1 PM, respectively. The initial total N of 0.14% was reduced to 0.12% with applications of 6 and 8 t ha^?1 PM but to 0.11% with the other treatments in the first planting; but reduced to 0.08% with applications of 2 and 4 t ha^?1 PM and to 0.06 and 0.09% with applications of 8 and 10 t ha^?1 PM, respectively, in the second planting. Available P in the first planting was reduced from an initial 17.62?mg kg^?1 to 4.32?mg kg^?1with the control treatment and to 6.74 and 5.83?mg kg^?1 with applications of 2 and 4 t ha^?1 PM, respectively, but to 8.32 and 8.24 with applications of 8 and 10 t ha^?1 PM, respectively. In the second planting, it was reduced to 1.92?mg kg^?1with the control treatment and to 2.53 and 1.81?mg kg^?1 with applications of 2 and 4 t ha^?1 PM, respectively but to 1.90 and 1.56 with applications of 8 and 10 t ha^?1 PM, respectively. Application of 10 t ha^?1 PM supplying 19?kg N, 0.5?kg P and 27?kg K per ha was adequate for enhanced seed yield and proximate contents of “Egusi” melon.     

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.     

Diversified nitrogen rates influence nitrogen agronomic efficiency and seed yield response index of sesame (Sesamum Indicum,L.) cultivars

ABSTRACT

Due to elevating costs of N fertilizer and growing apprehensions about nitrate, experiments evaluating nitrogen agronomic efficiency (NAE) is becoming increasingly important in crop production. NAE and seed yield potentiality of three cultivars of sesame (Shandwel–1, Giza–32 and Sohag–1) were evaluated under four N applications (0, 72, 108, and 144 kg N ha^?1) in a field experiment. Results showed that Sohag–1 recorded the highest values of yield and yields traits surpassing the other two cultivars. Sesame plants received 144 or 108 kg N ha^?1 produced the highest seed yield. In plots fertilized by 108 or 144 kg N ha^?1, Sohag–1 was the potent cultivar for recording higher seed yield. N addition more or less than 108 kg N ha^?1 caused suppression in NAE. Sohag–1 was the most effective and responsive cultivar in N use being exceeded the averages of each seed yield at zero N rate and seed yield response index (SYRI).     

WHEAT RESPONSE TO FARM YARD MANURE AND NITROGEN FERTILIZATION UNDER MOISTURE STRESS CONDITIONS

Information on the combined use of organic and inorganic fertilizers on wheat (Triticum aestivum L.) productivity is lacking under moisture stress conditions of Northwest Pakistan. The present experiment was designed to ascertain the combined effect of organic and inorganic fertilizer management on rainfed wheat. Four levels of farm yard manure, FYM, (0, 10, 20, and 30 Mg FYM ha^?1) and nitrogen (0, 30, 60, 90, and 120 kg N ha^?1) were used. The experiment was conducted at the Agriculture Research Farm of NWFP Agricultural University Peshawar, Pakistan during crop season of 2003–04. The experiment was laid out in randomized complete block design with four replications. Plant height, productive tillers m^?2, grains spike^?1, grain yield, straw yield, and harvest index were significantly higher in plots which received 30 Mg FYM ha^?1. In the case of nitrogen (N) no distinctive differences between the effect of 90 and 120 kg ha^?1 was observed for most of the parameters. Nitrogen application at 90 kg ha^?1 had significantly higher; plant height, grains spike^?1, grain yield, straw yield, and harvest index as compared with the lower levels, i.e., 0, 30, and 60 kg N ha^?1 but were at par with 120 N kg ha^?1. Significantly higher numbers of productive tillers m^?2, grains spike^?1, grain yield, straw yield and harvest index were recorded with application of 30 Mg FYM ha^?1 + 90 kg N ha^?1. The present study suggested that application of 30 Mg FYM ha^?1 + 90 kg N ha^?1 are promising levels for higher production of wheat under moisture stress conditions. Further research work is needed to ascertain the effect of N above 90 kg ha^?1 under different moisture regimes.     

Phosphorus sources for winter oilseed rape (Brassica napus L.) during reproductive growth – magnesium sulfate management impact on P use efficiency

It has been assumed that phosphorus (P) resources accumulated in vegetative tissues of winter oilseed rape (WOSR) at flowering are too low to cover the requirements for the high-yielding crop during the seed filling period (SFP). The data used originated from field experiments with nutrients sequentially added to WOSR, using crops grown on soil rich in available P (2008–2010). The low-seed density canopies during SFP resulted only from the P remobilized from the pre-flowering crop resources. The high-seed density canopies depended on both P remobilized and its uptake from soil (PFPU). The maximum PFPU of 30.7 kg P ha^?1, and the concomitant seed density of 86.8 ? 10³ m^?2, resulted in a maximum seed yield of 5.8 t ha^?1. Internal P resources were reused during SFP irrespective of the initial P content and without impact on phosphorus use efficiency (PUE). The study showed that PUE improvement in WOSR is related to the seed density of primary branches. Its development depended on the supply of potassium, magnesium and sulfate. A PUE of 105.4 kg seed kg^?1 P was used to predict the seed yield gap (PYG). This index can be used as a measure of P management efficiency in WOSR canopy.     

Assessment of long-term barley–legume rotations in a typical Mediterranean agro-ecosystem: grain and straw yields

Traditional Mediterranean rainfed cereal/fallow systems are being replaced by cereal monoculture due to land-use pressure. Food or forage legumes in rotation with cereals are an alternative sustainable cropping system. Complex cropping systems can only be assessed by long-term trials. This 11-year rainfed barley-based rotation trial in northern Syria assessed rotation effects on yields of barley and legumes, with particular emphasis on the management of vetch. The mean order of barley grain yields from the rotations was: vetch for hay, vetch for grazing > fallow = medic = vetch for seed > lentil, and continuous barley. Straw yields followed a similar pattern. Nitrogen (60 kg ha^?1) increased grain (39%) and straw (65%) yields. The N fertilization of barley had no carryover effect on the alternative legume crops. Although there were no significant differences in seed or straw yield between lentil and vetch, seasonal rainfall influenced overall yields. Total biomass yields were in the order of vetch, medic and lentil. There is a compelling case for annual vetch paired with barley in rotations for the Mediterranean region. Thus, barley/vetch rotations can potentially enhance barley yields and improve soil quality, and provide valuable fodder for small ruminants as well in the region's agricultural systems.