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Nutrient-use efficiency in pasture-crop rotations is not well understood. The hypothesis of this research is that nitrogen (N) cycled from the corn crop to the following pasture is not enough to supply the N demand of the pasture, independent of pasture height management. Our goal was to assess the carryover effect of N-fertilization from corn crop to a mixed pasture of black oat and ryegrass managed with two sward heights in an integrated crop-livestock system. The experimental design was a factorial arrangement (2 × 2) of sward height (10 and 25 cm) and N pasture fertilization: 0 kg N ha−1 (representing the carryover of N-fertilization from the corn crop) and 200 kg N ha−1. Accumulated forage dry matter and N concentration increased by 62% and 40%, respectively, in the pasture-fertilized compared with fertilization only in the previous crop phase. The residual effect of N applied to the previous corn crop was not enough to adequately meet the N requirements of the subsequent pasture, thereby reducing forage dry matter accumulation compared with the pasture-fertilized system. Our data suggest that fertilization of the pasture phase is key to better nutrient use efficiency in integrated crop-livestock systems. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate whether biochar, produced by pyrolysis at 300°C from rice husk and grape pomace (GP), affects plant growth, P uptake and nutrient status. A 3-month period of ryegrass(Lolium perenneL.) cultivation was studied on two Mediterranean agricultural soils. Treatments comprised control soils amended only with compost or biochar, and combinations of biocharpluscompost, with the addition of all nutrients but P (FNoP) or without any fertilization at all (NoF). Application of both types of biochar or/with compost, in the presence of inorganic fertilization except P, significantly increased (P < 0.05) dry matter yield of ryegrass (58.9–77.6%), compared with control, in sandy loam soil, although no statistically significant increase was observed in loam soil. GP biochar and GP biocharpluscompost amended loam soil harvests gave higher P uptake than control, in the presence of inorganic fertilization except P, whereas in sandy loam soil, a statistical increase was recorded only in the last harvest. In addition, Mn and Fe uptake increased with the addition of the amendments in both soils, while Ca increased only in the alkaline loam soil. Biochar addition could enhance ryegrass yield and P uptake, although inorganic fertilization along with soil condition should receive special attention. [ABSTRACT FROM AUTHOR]

The effect of compost application on the chemical soil properties, which are important for soil fertility, was analysed. Pot experiments were set up before and after incubation of soil mixed with compost. Four treatments include 0, 2.5, 5 and 10 m/m % compost mixed to soil were used; each treatment was repeated four times. Compost was from plant residues, and soil (Luvisol) from agricultural land of Gödöllő. Ryegrass (Lolium perenne) was seeded in the pots. The pots were set up at standard 20°C in a climate room, irrigated daily to 60% of field capacity, and cut after three and four weeks. During the incubation monthly, the hot water percolation-soluble C and N content was analysed. After cutting the ryegrass, plant weight was measured and N, P and K content of plants was analysed. Soils with higher compost ratio show a higher C, N P and K content. The plant analysis for both the not incubated and soils incubated with different compost portions show the following differences: fresh and dry plant weight and N, P and K content of the treatment with 10 m/m % compost increased significantly. Hot-water-soluble N content increased continuously during the six months of incubation, while C content decreased. [ABSTRACT FROM AUTHOR]

Determining potassium (K) fertilizer requirement using sorption isotherms is considered more accurate than conventional soil K tests. A total of 59 surface soil samples were used to establish K exchange isotherm. To evaluate K requirement sorption test, a glasshouse experiment using perennial ryegrass (Lolium perenne, cv. Roper) was carried out on 10 soil samples. The experiment was laid out as a completely randomized design with four replications and four K levels (K0, K20, K40, K80). Concentrations of K in solution established by adding K in the pots estimated from the sorption curve ranged from 20 to 80 mg K l-1 including check treatment (no K). Dry matter yield of ryegrass in most soils approached maximum as adjusted K levels were increased to 20 mg K l-1. The amounts of K required to bring the soils to 20 mg l-1 in soil solution varied among soils and ranged from 99 to 399 mg kg-1, on average 205 mg kg-1 soil. It was found that a useful regression model for the prediction of standard K requirement (K20) included the combination of plant available K extracted by NH4OAc (Av-K) and clay content: K20 = -41 - 0.63 Av-K + 9.0 Clay (R2 = 0.61, p < 0.001, n = 59). [ABSTRACT FROM AUTHOR]