Effects of seed rate,nitrogen level and leaf age on the yield of extracted protein from five different crops in West Bengal

The yield of leaf protein from five different crops grown at different seed rates and nitrogen levels was studied. Bajra (Pennisetum typhoideum Rich.) and mustard (Brassica nigra Koch) gave large protein yields. Harvesting just before the initiation of flowering produced the highest yield except with hybrid Napier (P. typhoideum x P. purpureum) and turnip (Brassica rapa L.). With the latter, maximum yield was obtained 45–52 days after sowing, and with the former 62 days. Seed rates of 120–150 kg/ha (4–5 times normal) were used with bajra and ragi (Eleusine coracana Gaertn), 30 kg/ha with mustard and 8 kg/ha with turnip. The yield of extracted protein was not increased by giving mustard more than 60, ragi more than 160 and bajra more than 240 kg N/ha. The N level for maximum response was not reached with turnip and hybrid Napier. More of the leaf protein was extracted from mustard and turnip than from the other species; mustard and turnip also gave the largest yields of protein (7.6 and 5.7 kg/ha/day respectively).     

Prediction by leaf analysis of nitrogen fertilizer required for winter wheat

In 1966 and 1967, 12 experiments on winter wheat tested five rates of N applied in spring as NH₄NO₃. Leaf samples comprising all the above ground vegetation were taken on two dates in spring between 31 March and 18 May from a fixed area of crop grown without fertiliser N; the dry matter yield (DM, kg/ha) and N content (%) were determined. Between the two dates, DM increased and leaf N content decreased. From the response curves for N applied and grain yield, the optimum rate of fertilizer N required for maximum grain yield was obtained. The latter was used as a test of soil N availability and compared with the following values (i) content of N (%) in leaves at each sampling and its rate of decrease—no significant correlation, (ii) yield of leaf DM (kg/ha) at first sampling—no significant correlation, (iii) leaf DM yield at second sampling, significant (r= -0.678), and also rate of increase in DM (kg/ha per day, r= -0.711), (iv) leaf N offtake (kg/ha N) significant at first sampling (r= -0.607), second sampling (r= -0.744) and also rate of increase in N offtake (kg/ha N per day, r= -0.670). Crop growth in spring was related to N supply and it was shown that DM yield, leaf N offtake and their respective rates of increase could be used to assess the availability of N in the soil and to predict the amount of N fertilizer required in spring to obtain maximum grain yield.     

不同光叶紫花苕子翻压量对烤烟产量和品质的影响

采用田间小区试验的方法探讨了施用70％化肥条件下不同光叶紫花苕子翻压量对烤烟生长发育以及烟叶产量、产值和化学成分含量的影响.结果表明,翻压适量的绿肥能够促进烟株的生长,尤其是叶片的开片;增加烟叶的SPAD值;提高烟株干物质积累量及烤后烟叶的产量,改善烟叶的化学品质.当翻压22 500 kg/hm2绿肥时,烟叶的产量、产...     

A preliminary study of the agronomic factors affecting the yield of extractable leaf protein

Several species have been selected for their ability to synthesise protein rapidly. The main factors influencing their protein production were nitrogenous fertiliser, age at harvest, seed rate and climate. Some of the best species were grown either alone or in sequence at optimum rates of seed and N, and harvested to make maximum use of the growing season. The annual yields of extracted protein reached 2000 kg/ha in a good year with winter wheat followed by two crops of mustard or fodder radish. The grasses have not extracted well in the past; however, with recent improvements in agronomy and machinery, cocksfoot yielded 1670 kg/ha in a very dry year and can be expected to yield 2000 kg/ha regularly in wetter parts of the British Isles. It is hoped that similar knowledge will lead to much higher yields in the wet tropics.     

Effect of sodium and magnesium fertilisers and irrigation on growth, composition and yield of sugar beet

Field experiments (1968–70) were made to find how sodium and magnesium fertilisers and irrigation affect yield of sugar beet. 0 and 250 kg/ha sodium (as agricultural salt) and 0 and 100 kg/ha magnesium (as kieserite) were tested; also no water and irrigation, to prevent the calculated soil moisture deficit from exceeding 40 mm. The plants contained most sodium during August when plants not given it contained 80 kg/ha and plants given it contained 145 kg/ha. Measured losses of sodium and potassium from the soil equalled the total taken up by the crop. Sodium and irrigation increased the leaf area index and total dry matter of the crop. The average increase in sugar yield was 0·5 t/ha from sodium and 0·68 t/ha from irrigation. From late July onwards, irrigated plants had slightly fewer leaves than unirrigated ones. Plants given sodium had more of their total dry matter in the roots than those not given sodium. The effects of sodium and irrigation were additive. Magnesium fertiliser increased the concentration of magnesium in the plants and their total content, but had no effect on growth, uptake of the other cations or final yield of the crop. It is concluded that sodium increased sugar yield by increasing the leaf area index early in the season and by increasing the proportion of the total dry matter partitioned to the roots; irrigation also appeared to act partly by increasing leaf area index but it also greatly increased the uptake of nutrients.     

Effect of spring grazing date and stocking rate on sward characteristics and dairy cow production during midlactation

The objective of this study was to investigate the effect of initial spring grazing date and subsequent stocking rate on sward characteristics, grazing behavior, milk yield, and dry matter intake of spring-calving dairy cows during the main grazing season. Sixty-four spring-calving Holstein-Friesian dairy cows (58 ± 9 d in milk) were balanced and randomly assigned to 1 of 4 grazing treatments (n = 16) between April 12, and July 3, 2004. Two swards, an early-grazed (E) sward and a late-grazed (L) sward had 2 stocking rates, high and medium, imposed across them. Cows grazing the E swards were stocked at 4.5 cows/ha (E4.5) and 5.5 cows/ha (E5.5), whereas cows grazing the L sward were stocked at 5.5 cows/ha (L5.5) and 6.4 cows/ha (L6.4). Sward characteristics, grazing behavior, and grass dry matter intake (GDMI) were investigated during the second (R2) and fourth grazing rotations (R4). Total dry matter yield was greater on L swards in R2. In R2, the E swards had a greater proportion of leaf as well as a lesser stem and dead dry matter yield. During R2, organic matter digestibility and crude protein content were greater on the E sward than the L sward. Pre-and postgrazing heights were greater for the L swards in R2 and R4. In R4, there was a larger leaf allowance on the E swards. Grazing time was greater and ruminating time lesser for animals grazing the E sward in R2. During R4, intake per bite was greater for the E5.5 and E4.5 treatments. Milk and solids-corrected milk yields as well as GDMI were greater for animals grazing the E sward in both R2 and R4. The results of the present study suggest that early grazing initially had a positive effect on sward quality and structure, which resulted in improved grazing behavior characteristics, increased GDMI, and increased milk production. During R4, sward quality and structure were similar between swards; thus, differences in grazing behavior were due to divergent daily herbage allowances. These results suggest that sward structure and quality as well as daily herbage allowance are important factors that influence animal performance and grazing behavior.     

Studies on the performance of tetrakalai (Phaseolus aureus Linn) as a leaf protein crop in West Bengal.

Tetrakalai, the tetraploid form of Phaseolus aureus, was studied in the fields of the Indian Statistical Institute, Calcutta, in 1970, 1971 and 1972 to investigate its leaf protein yielding potentialities. In 1972 the yield of extracted leaf protein (LP) reached 458 kg/ha in 95 days, from harvests at 53 days along with the first regrowth cut. Of the two seed rates tried, 100 kg/ha, i.e. four times the conventional rate, gave a greater yield of protein than 50 kg/ha. Although not statistically significant, better protein yields were obtained with an increase in phosphate dose up to the 120 kg/ha level.     

Nutritional composition and in vitro digestibility of grass and legume winter (cover) crops

In dairy farming systems, growing winter crops for forage is frequently limited to annual grasses grown in monoculture. The objectives of this study were to determine how cropping grasses alone or in mixtures with legumes affects the yield, nutritional composition, and in vitro digestibility of fresh and ensiled winter crops and the yield, nutritional composition, and in vitro digestibility of the subsequent summer crops. Experimental plots were planted with 15 different winter crops at 3 locations in Virginia. At each site, 4 plots of each treatment were planted in a randomized complete block design. The 15 treatments included 5 winter annual grasses [barley (BA), ryegrass (RG), rye (RY), triticale (TR), and wheat (WT)] in monoculture [i.e., no legumes (NO)] or with 1 of 2 winter annual legumes [crimson clover (CC) and hairy vetch (HV)]. After harvesting the winter crops, corn and forage sorghum were planted within the same plots perpendicular to the winter crop plantings. The nutritional composition and the in vitro digestibility of winter and summer crops were determined for fresh and ensiled samples. Growing grasses in mixtures with CC increased forage dry matter (DM) yield (2.84 Mg/ha), but the yield of mixtures with HV (2.47 Mg/ha) was similar to that of grasses grown in monoculture (2.40 Mg/ha). Growing grasses in mixtures with legumes increased the crude protein concentration of the fresh forage from 13.0% to 15.5% for CC and to 17.3% for HV. For neutral detergent fiber (NDF) concentrations, the interaction between grasses and legumes was significant for both fresh and ensiled forages. Growing BA, RY, and TR in mixtures with legumes decreased NDF concentrations, whereas growing RG and WT with legumes did not affect the NDF concentrations of either the fresh or the ensiled forages. Growing grasses in mixtures with legumes decreased the concentration of sugars of fresh forages relative to grasses grown in monoculture. Primarily, this decrease can be attributed to low concentrations of sugars of mixtures with HV (10.5%). Growing grasses in mixtures with legumes reduced the fiber digestibility of both winter crops (75.7% to 72.8% NDF). Growing grasses in mixtures with legumes did not affect estimated DM yield, nutritional composition, or digestibility of the succeeding summer crops. In conclusion, growing grasses in mixtures with legumes as winter forage crops can increase forage estimated DM yields and its nutritional quality in dairy farming sytems.     

The yields of extracted leaf protein from lucerne (Medicago sativa L.)

The effects of fertilisers, frequency of cutting, row spacing and simazine on the yields of dry matter and extractable protein from lucerne (Medicago sativa L.) were studied using the laboratory-scale pulper and press. Between 40 and 65% protein nitrogen was extractable; extractability was not affected by the various treatments but altered with season. Lucerne responded with increased yields of dry matter and extractable protein to fertilisers, simazine (35 g/ha) and rows spaced at 30.5 cm. Six or 8 harvests were found to give greater yields than 5 harvests in 180 days. The annual yields of extractable protein reached 3100 kg/ha and it is felt that better control of pests could lead to even greater yields.     

Leaf analysis as a guide to the nutrition of fruit crops. X. Magnesium and phosphorus sand culture experiments with apple

Sand culture pot experiments were carried out on young virus-tested dessert apples, on MM.104 rootstocks, to study the effects of different levels of nutrient Mg and P on growth, flower production, crop yield and leaf nutrient composition. The relationship between leaf nutrient status and growth and fruiting was also investigated with a view to establishing “critical” leaf nutrient values for Mg and P. Variations in leaf Mg, over the range 0.07 to 0.33% Mg in dry matter (August sampling), had no significant effect (5% level) on growth and fruiting, although magnesium deficiency symptoms appeared on trees with leaf values less than 0.15% Mg in dry matter. Sub-clinical concentrations of leaf P had very pronounced effects on growth, flowering and yield. Raising leaf P (July) from 0.15 to 0.25% P in dry matter doubled the number of flowers (in some years) in the following season and substantially increased growth and crop yield. In the absence of other limiting factors, and with adequate levels of N, the “critical” leaf P level in July—August would appear to be in the region of 0.25% P in dry matter.     

Tiller Development Influences Seasonal Change in Cell Wall Digestibility of Big Bluestem(Andropogon gerardii)

The productivity of cool-season forage grasses declines during mid-summer in the southern corn belt of the USA. Warm-season grasses are productive during this time, but their digestibility decreases from spring to summer. The objective of this study was to investigate cell wall factors contributing to the decline in in vitro dry matter digestibility (IVDMD) of big bluestem ( Andropogon gerardii Vitman) leaf blades from late spring (May) to mid-summer (July) under three harvest regimens. Under frequent defoliation, decrease in cell wall digestibility accounted for much of the change in IVDMD. Among cell wall constituents, only xylose and alkali-labile phenolic acids increased significantly from spring to summer. Change in p -coumaric acid content and the ratio of p -coumaric acid to ferulic acid were both negatively correlated with the decrease in cell wall digestibility. While glucose and uronic acid digestibility decreased from spring to summer, xylose was consistently the least digestible of the cell wall monomers. In warm-season grasses grown under constant environments, tiller development causes an increase in leaf structural tissue, and the data suggest that the seasonal decline in leaf blade cell wall digestibility was partially due to tiller development.     

Multi-year evaluation of stocking rate and animal genotype on milk production per hectare within intensive pasture-based production systems

The objective of this experiment was to evaluate the effect of stocking rate (SR) and animal genotype (BR) on milk production, body weight (BW), and body condition score (BCS) within intensive pasture-based systems. A total of 533 lactation records, from 246 elite genetic merit dairy cows were available for analysis; 68 Holstein-Friesian (HF) and 71 Jersey × Holstein-Friesian (JxHF) crossbred cows in each of 4 consecutive years (2013–2016, inclusive). Cows from each BR were randomly allocated to 1 of 3 whole-farm comparative SR treatments, low (LSR; 1,200 kg of BW/ha), medium (MSR; 1,400 kg of BW/ha), and high (HSR; 1,600 kg of BW/ha), and remained in the same SR treatments for the duration of the experiment. The effects of SR, BR, and their interaction on milk production/cow and per hectare, BW, BCS, and grazing characteristics were analyzed. Total pasture utilization per hectare consumed in the form of grazed pasture increased linearly as SR increased: least in LSR (10,237 kg of dry matter/ha), intermediate in MSR (11,016 kg of dry matter/ha), and greatest in HSR (11,809 kg of dry matter/ha). Milk and milk solids (MS) yield per hectare was greatest for HSR (15,942 and 1,354 kg, respectively), intermediate for MSR (14,191 and 1,220 kg, respectively), and least for LSR (13,186 and 1,139 kg, respectively) with similar trends evident for fat, protein, and lactose yield/ha. At higher SR (MSR and HSR), MS yield per kg of BW per ha was reduced (0.85 and 0.82 kg of MS/kg of BW, respectively) compared with LSR (0.93 kg of MS/kg of BW/ha). Holstein-Friesian cows achieved fewer grazing days per hectare (?37 d), and produced more milk (+561 kg/ha) but less fat plus protein (?57 kg/ha) compared with JxHF cows; the JxHF cows were lighter. At similar BW per hectare, JxHF cows produced more fat plus protein/ha during the grazing season at low (1,164 vs. 1,113 kg), medium (1,254 vs. 1,185 kg), and high (1,327 vs. 1,380 kg) SR. In addition, JxHF cows produced more fat plus protein per kg of BW/ha (0.90 kg) compared with HF cows (0.84 kg). The results highlight the superior productive efficiency of high genetic potential crossbred dairy cows within intensive pasture-based production systems.     

富磷土壤磷肥用量对烟株养分累积和烤烟产质量的影响

为探明富磷植烟土壤的适宜施磷量,通过大田试验,研究不同施磷量（0、63、94.5、126、157.5和189 kg/hm²）对烟株养分累积和烤烟产质量的影响。结果表明：（1）随施磷量的提高烤烟各部位干物质累积量呈先增加后降低的趋势。（2）与对照相比,施磷量为94.5~189 kg/hm²时均能提高烤烟叶片、地上部和植株氮磷钾养分累积量,且以施磷量157.5 kg/hm²为最高。（3）施磷量为94.5 kg/hm²时烤烟产量、上等烟比例和产值均最高,分别较其他处理增加了4.24%~23.29%、1.93~17.36百分点和3.26%~37.46%。（4）当施磷量为94.5和157.5 kg/hm²时磷素表观利用率较高,且显著高于对照和施磷量63 kg/hm²处理。（5）富磷土壤上过多施用磷肥（157.5和189 kg/hm²）有降低上部烟叶油分和中部烟叶香气量的趋势。因此,对于恩施州富磷土壤,建议磷肥推荐用量为94.5 kg/hm²。     

不同氮素水平对烤烟生长发育的影响

研究了不同氮素水平下烤烟的大田生长发育规律。结果表明：除严重缺氮（未施氮）外，不同氮素水平对出叶速度和总出叶数没有影响；随着氮素水平提高，田间叶面积系数、烟株最大叶面积和地上部干物质量不断增加，氮素过量造成的烤烟过度生长主要是从旺长后期开始的；适宜氮素用量（本试验为６ｋｇ氮／亩）烤烟旺长前、旺长期和成熟期的干物质积累比例分别为１５％、６０％和２５％，经济系数约为７５％。     

Prediction of the digestibility of the dry matter of tropical forages from their solubility in fungal cellulase solutions.

Correlations between in vitro dry matter (DM) digestibility and amount of DM dissolved in acid pepsin and cellulase enzymes for 24 tropical forage samples gave a value of 0.91 but a high sample standard deviation of 6.50 and a coefficient of variation of 25 %. This suggests that the cellulase technique requires further study if it were to be used as a predictor of rumen liquor in vitro digestibility values for tropical grasses and legumes. An improved correlation of r = 0.98 with sample standard deviation of 2.29 was obtained when percent DM dissolved in acid-pepsin and cellulase enzymes was compared with the in vivo dry matter digestibility values of 11 tropical forage grasses and legumes. This result suggests that the pepsin-cellulase technique may be used to predict in vivo DM digestibility values in tropical grasses and legumes.     

Yields and Nutritive Value of Cuttings of Permanent Pasture Harvested as Dried Forage

Four .12-ha plots were outlined in an area of permanent pasture. Two were harvested initially on May 17 and two on May 24. One plot from each then was treated with nitrogen at 56 kg/ha. Three subsequent cuttings were when plant regrowth had reached 25 to 30 cm or when vegetative growth had ceased. Forages were sampled at cutting and after drying in the field and later under a barn roof. Material harvested on common cutting dates was combined and fed to four lactating cows in a series of digestion trials. First harvest on May 17 resulted in higher seasonal yield of dry matter than that for the May 24 cutting, 7,219 versus 5,687 kg/ha. Pasture cuttings averaged 17.2% crude protein, 28.6% acid detergent fiber, and 73.4% in vitro digestibility. Animal digestibilities of the dried pasture cuttings were high for first and fourth cuttings (digestible dry matter 76 to 79%) and lower for midsummer harvest (digestible dry matter 56%).     

Leaf and Stem In Vitro Digestibility for Grasses and Dicotyledons of Meadow Plant Communities in Spring

The aim of this study was to improve prediction of the herbage digestibility of meadow plant communities rich in species. The variability of the in vitro dry matter digestibility (IVDMD) at a given date could result both from the species which constitute the plant community and from the variability in the proportion of the different plant components in relation to growth conditions. In order to separate the two factors, we studied the IVDMD change in spring, through the NIRS procedure, one month before and one month after the flowering stage of the main species. This was done for two sets of plant communities with very different botanical composition, dominated by species such as Dactylis glomerata and Chaerophyllum aureum (three) or Festuca rubra and Sanguisorba minor (two plant communities). The IVDMD of dicotyledons was higher than those of grasses both for leaf blades and for stems. The leaf blade IVDMD was quite stable throughout the period studied while those of grasses decreased by about 100 g kg^-1. The stem IVDMD for grasses as for dicotyledons first decreased quickly the month before the flowering stage of the main species, and then move slowly the next month. The difference in IVDMD between those species which were mostly in nutrient-rich habitats was 20 (stems of dicotyledons) to 80 g kg^-1 (leaf blades of grasses) higher when compared to those species which were mostly in nutrient-poor habitats. These results, obtained for leaf blades and stems of sets of species with different habitat characteristics, were in agreement with those of the literature on swards which are almost always pure. For modelling the digestibility change for such plant communities through a growth period, we propose to use the IVDMD values characteristic of a given set of species, as outlined above, and the proportion of the different plant components in the herbage. © 1997 SCI.     

Solvent fractionation of leaf juice to prepare green and white protein products

The effectiveness of organic solvents in the separation of pigmented protein from leaf juice was studied, thus permitting the recovery of a non-pigmented protein suitable for use in human foods. Juices extracted from lucerne (Medicago sativa L.), tall fescue (Festuca arundinacea L. var. Alta) and Italian ryegrass (Lolium multiflorum L. var. RVP) were studied. The yield of ?white’? protein from lucerne was double that from the grasses and it was lighter in colour. Of 20 solvents tested, 13 promoted the separation of chloroplastic material. These were in two categories: solvents with limited water solubility which were effective at a 3-4% (w/w) concentration and highly polar solvents which were effective at a 10-12% (w/w) concentration. Solvents of high specific gravity were not effective. Various conditions of solvent concentration, temperature and pH were studied with representatives of both groups of solvents in order to optimise the yield of ?white’? protein. Solvent fractionation, as a method of preparing a non-pigmented protein concentrate, is discussed in relation to differential heat treatment of leaf juice and solvent extraction of whole leaf protein concentrate. The potentials of these concentrates in human foodstuffs is compared.     

Net effects of nitrogen fertilization on the nutritive value and digestibility of oat forages

Applications of soil amendments containing N are part of routine forage-management strategies for grasses, with a primary goal of increasing forage yield. However, the effects of N fertilization on forage nutritive value, estimates of energy density, and in vitro dry matter or neutral detergent fiber disappearance sometimes have been erratic or inconsistent. Our objectives were to evaluate the effects of N fertilization on the nutritive value of a single cultivar (ForagePlus, Kratz Farms, Slinger, WI) of fall-grown oat fertilized at planting with 20, 40, 60, 80, or 100 kg of N/ha of urea or 2 rates of dairy slurry (42,300 or 84,600 L/ha). Nitrogen fertilization exhibited consistent effects on fiber components; forages fertilized with urea or dairy slurry had greater concentrations of fiber components compared with those harvested from unfertilized check plots (0 kg of N/ha), and fiber concentrations increased linearly with urea fertilization rate. In contrast, concentrations of water-soluble carbohydrates were greatest for unfertilized forages (21.2%), but declined linearly with urea fertilization, exhibiting a minimum of 13.5% at the 80 kg of N/ha urea application rate. Similarly, nonfiber carbohydrates also declined linearly, from 34.8% for unfertilized check plots to a minimum of 24.6% at the 80 kg of N/ha urea application rate. Fertilization with urea resulted in consistent linear increases in crude protein (CP), neutral detergent soluble CP, neutral detergent insoluble CP, and acid detergent insoluble CP; however, the partitioning of CP on the basis of association with specific fiber fractions could not be related to N fertilization when concentrations were expressed on a percentage of CP basis. The summative calculation of energy, expressed as total digestible nutrients was closely related to N fertilization rate during both the 2013 (y = ?0.038x + 72.2; R² = 0.961) and 2014 (y = ?0.040x + 69.2; R² = 0.771) production years. Following 30- or 48-h incubations in buffered rumen fluid, in vitro dry matter disappearance was greater for unfertilized forages compared with those fertilized with either urea or dairy slurry, and disappearance declined linearly with urea fertilization rate; however, these responses were not detected for neutral detergent fiber disappearance. Overall, the forage nutritive value of fall-grown oat declined mildly in response to N fertilization, but these responses were not nearly strong enough to offset the advantages obtained by improved forage yields.     

种植密度与施氮量对江西紫色土烤烟产量及农艺性状的影响

为了查明江西紫色土上种植模式与浓香型烟叶质量的关系,以江西省主栽烤烟品种K326为试验材料,研究种植密度与施氮量互作对烤烟产量及农艺性状的影响。结果发现,增施氮肥后株高显著增高、烟叶显著增宽、叶长/宽显著减小、烟叶鲜重/干重显著提高。当施氮量≤142.5 kg/hm²时,株距越小烟叶越宽,烟株密植能显著提高烟叶产量;但当施氮量≥142.5 kg/hm²时烟株稀植有利于上等烟比例的提高;当施氮量为165 kg/hm²时,烟株稀植有利于叶长与叶宽的增加,同时显著提高上等烟比例;当施氮量为165 kg/hm²、株距为0.5 m时,烤烟产量与产值均最高。故建议今后紫色土烤烟种植模式为行距1.2 m,株距0.5 m、施氮量165 kg/hm²。