Effects of Plant Density on Forage Nutritive Value of Whole Plant Corn

In the field experiment, the effects of plant densities (75 000, 112 500 and 150 000 plants ha-1) on forage nutritive value of whole plant corn (WPC) were studied from 1999 to 2001. The results demonstrated that with the increasing of plant density, the forage matter yield per plant corn decreased significantly, while the fresh matter and dry matter per hectare corn increased significantly, and a higher grains yield was gotten at higher plant densities. Forage nutritive quality of whole plant corn was changed as plant density increased, the crude protein (CP), ether extract (EE), crude fiber (CF), nitrogen free extract (NFE) and general energy (GE) yields increased obviously. Increas- ing plant density reasonably with the application of plant growth regulators could improve plant properties, harvest more forage matter, and enhance forage nutritive value of WPC.

Effects of Different Nitrogen Application Strategies on Yield and Forage Nutritive Quality of Zea mexicana

A pool experiment was carried out to study the effects of different nitrogen applicationstrategies (rates and stages of nitrogen application) on yield and forage nutritivequality of Zea mexicana cultivated in summer, 2002. In the whole growing stage, its stemwas clipped three times at the height of 25cm when it was 110cm high (H1, H2 and H3 standfor the first, second and third harvest stage, respectively). Six indexes includingcrude protein (CP), ether extract (EE), nitrogen free extract (NFE), acid detergentfiber (ADF), crude ash (CA), and general energy (GE) were employed to evaluate the foragenutritive value. The results showed that the content of CP and EE increased but thecontent of CA and ADF decreased under the two nitrogen rates (High-rate N, 600kgha-1;Mid-rate N, 300kgha-1). The fresh and dry harvest biomass of the whole plants on H1 andthose of the leaves on H2 were also improved. But the stalks on H2 and the whole plantson H3 were affected mainly by dressing nitrogen fertilizer. The yield of CP and EE, CA,NFE, and GE was mainly affected by nitrogen rates. The ADF yield increased was due to theincrement of the fresh and dry harvest biomass. Nitrogen applied as base fertilizer forsummer Zea mexicana can be harvested a higher biomass and improve the forage nutritivequality.

Classification of plant functional types based on the nutrition traits： a case study on alpine meadow community in the Zoigê Plateau

The ecological concept of Plant Functional Types（PFTs）, which refers to the assemblage of plants with certain functional traits, has been introduced for the study of plant responses to the environment change and human disturbance. Taking the alpine meadow community in the Zoigê Plateau as a study case, this paper classified PFTs in terms of plant nutrition traits. The sequential results are as follows.（1） The main herbages in the Zoigê Plateau included 16 species in 5 families. Among the five families, Cyperaceae vegetation accounted for 81.37%of herbage area in total, while the remaining 4families occupied less than 20%. As for the species,Kobresia setchwanensis Hand.-Maizz. was dominant,accounting for 48.74% of the total area; while the remaining 51.26% was comprised of Polygonum viviparum L., Anaphalis fiavescens Hand.-Mazz.,Stipa aliena Keng and other species.（2） By using the Principal Component Analysis（PCA）, the assessment of herbages nutrition was carried out based on the comprehensive multi-index evaluation model.Polygonum viviparum L. had the highest nutritional value score（1.43）, and Stipa aliena Keng had the lowest（-1.40）. Nutritional value of herbage species had a significantly positive correlation with altitude（P＆lt;0.01） in the Zoigê Plateau.（3） Based on the nutritional values, herbages in the Zoigê Plateau could be grouped into 3 nutrition PFTs（high, medium and low） by using the Natural Breaks（Jenks） method.

Exploring the impact of soil water variability and varietal diversity on alfalfa yield,nutritional quality,and farm profitability

Background:Despite high nutritional and economic value,alfalfa yield has not been improved in the United States.Soil moisture critically influences alfalfa's yield and quality,affecting its physiological processes,nutrient uptake,and stand growth.Additionally,the maturity stage at harvest can significantly impact both hay yield and quality.Thus,this study aimed to assess the effect of different soil moisture levels and harvesting times on forage yield,nutritive value,and the overall profitability of commercially cultivated alfalfa.Methods:Two conventional and three lower-lignin alfalfa varieties were planted in a randomized complete block with split plot design under drought,rainfed,and irrigation conditions in 2020 in Manhattan,Kansas,USA.The dry matter yield(DMY)and forage nutritive value were evaluated at late bud,early flowering,and 7 days after early flowering stages,respectively.Results:DMY varied with production year,soil water availability,and growth stages,with drought conditions causing a decline in DMY of 5%to 38%in the second production year.Water conditions and maturity stages influenced crude protein(CP)and in vitro dry matter digestibility(IVDMD).Higher soil moisture and advancing maturity stages negatively impacted CP,IVDMD,and relative forage quality.The study revealed net profit margins of 62%,64%,and 52%for drought-prone,rainfed,and irrigated production,respectively.Conclusions:Harvest timing and irrigation practices were found to have substantial implications for forage yield and nutritive value of alfalfa.The yield-quality trade-off differed under drought and irrigation,with early harvesting leading to lower yields but higher protein content and digestibility.The study findings provide potential guidance for improving alfalfa hay yield,quality,and profitability.